Philosopher of Nominalism



Of those who readily acknowledged their great indebtedness to Scotus yet felt free to go their own way, the most significant philosopher was William of Ockham. An independent thinker who constantly criticized and sifted the teachings of Scotus, William went beyond the work of the great Master to inaugurate a new movement known as nominalism. In the second half of the fourteenth century, Thomism and Scotism were already called the "old way" (via antiqua) of philosophizing in contrast to the "modern way" (via moderna) of Ockham and his followers.






William was probably born at Ockham in the county of Surrey near London, around 1285. After joining the Friars Minor and his ordination as subdeacon in 1306, he pursued higher studies in theology at Oxford (1309-1315), when the ideas of Duns Scotus were very influential, and lectured on the Bible (c. 1315-1317) and on the Sentences (c. 1317-1319). Although he fulfilled all the requirements for the Master of Theology during the following two years, he never became a regent master occupying an official chair of theology but remained a "beginner" (hence the name Venerable Inceptor) due to the opposition of John Lutterell, Chancellor of Oxford University (1317-1322), who denounced Ockham as a heretic.

Pope John XXII summoned Ockham to Avignon where a papal commission (including Lutterell) found 51 propositions extracted from his writings, open to censure. Although Ockham was not formally condemned by the Pope, he was compelled to remain in Avignon along with Michael of Cesena, the minister general of the Friars Minor, who was opposed to the Pope on the interpretation of Franciscan poverty and the temporal power of the Church. Prompted by his general, William studied the papal constitution concerning the Franciscan rule and became firmly convinced that the Pope had fallen into heresy, thereby forfeiting his right to the Chair of Peter. For signing an appellation against the Pope and fleeing to Italy in 1328, both Ockham and Michael were excommunicated.

They joined Louis of Bavaria in Pisa on his return from Rome where he opposed John XXII by installing an antipope and receiving from him the crown of the Holy Roman Empire. In 1330 they journeyed with Louis to Munich, and remaining under his protection, aided him by their counsel and writings in his struggle against John XXII. Though there is no historical evidence of Ockham’s saying "O Emperor, defend me with your sword, and I will defend you with my pen," this famous dictum nevertheless expresses the fact of Ockham’s intellectual leadership in the struggle of the Emperor against the popes. During all this time, however, Ockham professed himself a faithful Catholic, willing to submit to the legitimate authorities of both the Church and the Franciscan Order though there is no evidence of a formal reconciliation. He died at Munich in 1347, probably a victim of the Black Death, and was buried in an old Franciscan Church.1




Ockham wrote his philosophical and theological works in Oxford (c. 1317-1323) and in Avignon (1324-1328) before his open conflict with the Papacy, and his polemical and political treatises in Munich (1330-1347). His works may be divided into logic, physics, theology, and politics.

- Logic.3 His works on logic include the following: Exposition on the Book of Porphyry (Expositio super librum Porphyrii): On Porphyry’s Introduction to Aristotle’s Categories, dealing with the five predicables — genus, species, difference, property, and accident; Exposition on the Book of the Predicaments (Expositio super librum Praedicamentorum): an explanation of Aristotle’s Categories, namely, substance and the nine accidents; Exposition on Two Books of the Perihermenias (Expositio super duos Libros Perihermenias): Aristotle’s On Interpretation,4 treating of propositions, and truth and falsity; Exposition on Two Books of the Elenchus (Expositio super duos libros Elenchorum): Aristotle’s On Sophistical Refutations, analyzing fallacies; Summa of All Logic (Summa totius logicae): Ockham’s main logical work dealing with terms, propositions, and arguments,5 definitely written before 1328 and probably after 1320; Compendium of Logic (Compendium logicae): a condensed presentation of logic, following the outline of the Summa of All Logic; Elementary (Elementarium):6 another systematic work on logic in a more personal style.

- Physics. Ockham’s writings on physics, which focus on the works of Aristotle, consists of three treatises: Exposition of the Books of the Physics (Expositio in libros physicorum); Summary on the Books of the Physics (Summulae in libros physicorum); and Questions on the Books of the Physics (Quaestiones in libros physicorum).

- Theology. Ockham’s theological works include the following: Ordination (Ordinatio): the first book of his commentary on the first book of the Sentences of Peter Lombard, dealing with God, was finished before 1323;7 Reportation (Reportatio): questions on the second, third, and fourth books of the Sentences, treating respectively of creation, redemption, and the end of man;8 Seven Quodlibetals (Quodlibeta septem): on far-ranging subjects; First Tractate on Quantity (Primus tractatus de quantitate), and Second Tractate on Quantity (Secundus tractatus de quantitate): these two tractates are on quantity in relation to the Holy Eucharist; Tractate on Predestination and on the Foreknowledge of God and of Future Contingents (Tractatus de praedestinatione et de praescientia Dei et de futuris contingentibus): on predestination and God’s knowledge of events depending on an act of free will;9 Various Questions (Quaestiones variae).

- Political and Polemical Writings.10 To Ockham’s Munich period belong the following principal political and polemical writings: The Work of Ninety Days (Opus nonaginta dierum): Allegedly written within ninety days (1333-1334) against Pope John XXII on the problem of Franciscan poverty; On the Dogmas of Pope John XXII (De dogmatibus papae Joannis XXII): polemical work against the Pope; Against John XXII (Contra Joannem XXII); Compendium of Errors of Pope John XXII (Compendium errorum papae Joannis XXII); Tractate showing that Pope Benedict XII and John XXII embraced heresies (Tractatus ostendens quod Benedictus papa XII nonnullas Joannis XXII haereses amplexus est et defendit); Allegations on Imperial Power (Allegationes de potestate imperiali); Eight Questions on Papal Power and Dignity (Octo quaestiones super potestate et dignitate papali); Whether the King of England can receive goods of the Church for the support of a war (An rex Angliae pro succursu guerrae possit recipere bona ecclesiarum); Dialogue (Dialogus): main work (1334-1338) on the relation between Church and State in the form of a dialogue, showing the pros and cons without revealing his own position (hence it must be used with caution); Tractate on the election of Charles IV (Tractatus de Electione Caroli IV); Breviloquium on the Power of the Pope (Breviloquium de potestate papae):11 on the spiritual and temporal power of the pope; Tractate on the Power of the Emperors and the Popes (Tractatus de imperatorum et pontificum potestate): on the Church at Avignon and the errors of John XXII.






Like other medieval philosophers and theologians, Ockham sought to understand his Christian faith in terms of philosophy. To this end, he needed to determine how much human reason, unillumined by divine revelation, can know. With the limits of cognition clarified, the problems of God, the world, and man can be investigated.


I. Cognition


At the outset, Ockham found it necessary to grapple with the issue of knowledge by laying a firm foundation to his philosophy. Like Aristotle, he investigated the conditions of scientific knowledge so as to distinguish strictly scientific from unscientific conclusions in philosophy and (revealed) theology. Such an inquiry could not be rigorously pursued without determining the very possibility and limits of human cognition as such. What is the mind able to know? What is it unable to know?

Scientific knowledge, according to Aristotle, concerns universals which are expressed in general statements predicable of many cases. What does the universal concept represent? Almost all of Ockham’s predecessors held that corresponding to the universality of a concept are natures or essences which in themselves have some kind of generality or commonness. Their problem was to show how universals become numerical units or singulars.

For Ockham, it was by no means self-evident that in its own right the nature or essence of a thing is not individual. Aristotle clearly stated what appears evident from immediate experience, namely, that only individuals exist. Consequently, Ockham regarded as a pseudo-problem the Scotistic questions of how common natures are individuated and the consequent issue of how the intellect can abstract a common nature from the individuals experienced. What is needed is not an explanation for the fact that something is an individual but an account of why it exists and that it has such or such a nature.

In one of those epoch-making changes of outlook, like Copernicus’ revolution in astronomy, Ockham strategically shifted the approach to the problem of universal concepts from the side of the universal to the side of the individual. For Ockham, the problem of individuation is a logical question of showing how general terms are used in propositions to refer to individuals. As an epistemological issue, the problem of universals is one of explaining how experience of individual existents can give rise to universal concepts holding for all objects signified by a term. To explain how universal concepts truly represent individuals in scientific knowledge, it is necessary to explain what makes a concept universal and what certainty there is of individual realities.

For Ockham, the Aristotelian and Thomistic theory of abstraction is inadequate by itself to guarantee intellectual knowledge of individual things. To achieve a rigorous scientific reexamination of the foundations of philosophy, Ockham found it necessary, as Aristotle had, to develop the practical science of logic so as to systematize universal concepts into an organized body of truths. What the mind scientifically affirms of reality, God, and creatures depends in large measure upon how it arranges its concepts and orders them in propositions.


II. Reality


Equipped with the scientific tool of logic, Ockham felt confident to investigate the problems of reality in general: the meaning of the term "being" and its relationship to both the conceptual and real order. In determining the sense of the term "being," Ockham believed that Scotus and Aquinas had confused the terminological and real order by affirming the reality of universality — a property of concepts — of the essences of things. One of Ockham’s main preoccupations was to distinguish what belongs to concepts and words from what constitutes the structure of reality.


III. God


Ockham objected to Scotus’ lack of strict scientific procedure in attempting to demonstrate the existence of God. Ockham’s task was to apply his logical tools in a rigorous critique of the Scotistic arguments, evaluating what could be demonstrated with certitude and what could be argued with probability.

As a Christian theologian, Ockham was passionately concerned with upholding the doctrines of divine omnipotence and liberty. He could not accept Scotus’ satisfaction that he had safeguarded the absolute freedom and power of God from ancient Greek necessitarianism by letting God be governed, as it were, and limited in his creative act by the eternal ideas or essences, and by endowing creatures with immutable natures and necessary relations. However, there was a long revered tradition behind the theory of ideas.

Bonaventure, Aquinas, and Scotus inherited the theory from Augustine who adapted it from the Neo-Platonists to explain God’s free and intelligent creation of the world. For Ockham to oppose the theory of ideas was like swimming against the current of history. Yet he was convinced that only by eliminating the metaphysics of essences implied in the theory of ideas and derived from Greek sources could he adequately preserve God’s omnipotence and liberty.

Ockham’s opposition to the metaphysics of essence is quite consistent with his attack against reification of universals. The postulation of ideas of universals in God, for example, the idea of human nature, arises from the need to account for some sort of universal in reality, for instance, human nature which all individual men have in common. Correlative to the theory of universal ideas in God is the acceptance of some form of "realism" in the explanation of one’s own universal ideas. By refuting the latter, Ockham found no need to assert the former. If a class-word like "man" objectively refers to no such thing as human nature, what is the sense of ascribing to God a universal idea of man, that is, an idea of human nature?

For a thorough criticism of Scotus’ approach to God, Ockham had to reexamine the Subtle Doctor’s doctrines of univocity and causality to see whether they justify man’s knowledge of God’s existence and essence. If only individuals exist, how can one univocally reason from creatures to God on the basis of a common characteristic in reality? Since arguments for the existence of God depend on the relation of effects to their cause, it is necessary to investigate the value of the principle of causality. What is the basis of the principle of causality?


IV. Creatures


Dissatisfied with Scotus’ study of man, Ockham was convinced that a strict scientific approach was needed to show what is certain and what is probable regarding the nature of the soul and its relation to the body. This same critical approach is needed to simplify Scotus’ complex conception of the world in terms of Aristotle’s categories. Ockham believed that Scotus had watered-down the contingency of creatures by adopting a Greek metaphysics of essence to establish an immutable natural law. Ockham was convinced that the moral order could be grounded in God without sacrificing his unconditional freedom or underestimating the radical contingency of creatures.


V. Politics


In the midst of controversy between the Papacy and the Holy Roman Empire, Ockham focused his attention on the special problem of the relation between State and Church, and sovereign and subjects. His immediate aim was to defend the lawful rights of the Franciscan Order and the "Holy" Roman Emperor, Ludwig of Bavaria, against the interference of Pope John XXII by determining the limits of papal power. This meant opposing the view of so-called curialist who claimed absolute universal power for the pope over temporal as well as spiritual matters. Ockham’s respect for law and custom led him to oppose arbitrary and capricious absolutism.




In his investigation of the problems of science, God, and creatures, Ockham centered his ideas around three themes: terms, freedom and power, and the individual.


I. Terms


Ockham advanced his inquiry by developing an epistemological position that radically distinguished him from Aquinas and Scotus. In contrast to the Thomistic and Scotistic conception of universal terms — as genera and species — with a real foundation in things, Ockham viewed concepts and names as signs that can refer to one thing or to many. Purely functional, their universality in no sense refers to a common nature possessed by many things outside the mind.

With universality as a construction of the mind, what assumes importance over metaphysics and physics is logic, the study of universal terms. Here Ockham shifted the focus of medieval philosophy from reality in itself — form, essence, and existence — to the terms signifying things in order to clarify metaphysical issues. This new notion of universality makes necessary a whole new logic of supposition in which terms stand, not for common natures, but for individual things. Having rejected the epistemological realism of Aquinas and Scotus, Ockham could criticize their metaphysical teachings and reconstruct the whole fabric of philosophy in view of his new logic.


II. Freedom and Power


Ockham’s epistemological stance grew out of his theological position. His restriction of universality to concepts arose from his view of the relation between God and creatures. The sufficient reason for affirming the truth of a statement cannot be found ultimately in merely contingent creatures, but only in God, the sole necessary being. Absolutely dependent on the omnipotent and unconditional free will of God, the world has no inherent reason to be what it is. Here Ockham diametrically opposed the necessitarianism of Greek and Arabic philosophers. In his search for truth, Ockham investigated beyond the contingent order of the present universe to discover what God can do by his absolute power, what is absolutely possible, and for that reason always true, free from contradiction, and therefore necessary. Ockham searched, not for what is relative, but for absolute truth.


III. Individual


Ockham’s viewpoint on universality as a construct of the mind also developed from the oft-repeated Aristotelian axiom that only individuals exist. Like Scotus, Ockham grounded scientific knowledge in the intuition of the individual thing which alone exists. "Knowledge of the singular sensible is absolutely first in this life, so that the same singular thing which is first perceived by the sense is the same object under the same aspect primarily understood intuitively by the intellect."12 With nothing in reality corresponding to universal concepts except individual things and qualities which are contingently related, universality can not be abstracted from reality but must be formally constructed by the mind. Ockham reaffirmed the uniqueness of the individual in the moral and political sphere. Each person possesses unique rights and freedom which are inviolable by any earthly power. In Ockham’s philosophy, the individual supercedes Aristotelian form, Thomistic existence, and Scotistic essence, as the ultimate reality.




Rigorous investigation of the problems of God, the world, and man demanded that Ockham develop a strict scientific method.


I. Scientific Knowledge


Ockham’s insistence on individuals as the sole existents did not prevent him from recognizing science as a knowledge of universal propositions. On the contrary, he accepted the Aristotelian dictum that science is of universal terms, quantified universally for all the individuals signified by the term. With a high ideal of strictly scientific knowledge modeled after that developed by Aristotle in his Posterior Analytics, Ockham defined science in the strict sense as "an evident cognition of some necessary truth caused by the evident cognition of necessary premises and a process of syllogistic reasoning."13 A proposition is scientifically known in this strict sense only when it remains true regardless of the existing world. All the truths of logic and mathematics, some statements about God (for example, God is good), and many metaphysical propositions, conform to the definition of scientific knowledge, for they are necessary conclusions obtained from evident premises which are necessary, that is, always true and never false.

In view of these requirements, no statement of actual fact about this world is truly a scientific statement. However, propositions about the world construed as conditionals or as of the mode of possibility may have the necessity required by the definition of scientific knowledge if they are based on evidence. For example, the proposition "Peter is moving" is necessary if considered as equivalent to the following hypothetical proposition, "If Peter is running, he is moving." Similar affirmative and assertoric propositions which include terms standing for contingent things can be necessary.

Ockham also accepted the Aristotelian notion of indemonstrable principles to which the mind assents once it grasps the meaning of the terms. Mathematical propositions are analytically evident from the meaning of the terms; for example, a triangle is a figure bounded by three sides. A principle may be indemonstrable inasmuch as it is known through experience. "Certain first principles are not known through themselves (per se nota or analytic) but are known only through experience as in the case of the proposition `all heat is calefactive.’"14 The premises of the natural sciences are also verified by intuitive cognition.


II. Real and Rational Science


To avoid the confusion of terms with things, Ockham distinguished between real and rational science. Whereas the former concerns things in reality, the latter focuses on terms which do not stand immediately for real things, as in the case of logic which deals with second intentions, for example, genus and species.

Without a clear distinction between these two types of sciences, concepts or terms will be confused with things. It is important, for example, to keep in mind that Aristotle’s intention in the Categories was to treat of words and concepts and not of things, otherwise one will misinterpret his thought. Logic deals with terms of second intention, "fabrications" or constructions of the mind’s activity without which they cannot exist. Since terms of second intention presuppose terms of first intention, logic as a rational science presupposes real science. However, real science, such as physics and metaphysics, deals with first intention. "The first intention is an act of the understanding signifying things which are not signs. The second intention is the act of signifying first intentions."15 Ockham’s inclusion of both sign and thing in the definition of first intention enabled him to account for two Aristotelian doctrines: first, science is of the universal; and second, only individuals exist. By means of universal terms, real science concerns individual things. In the universal proposition "man is capable of laughter," the universal terms stand for individual things, and not for any extramental universal reality. The difference between real and rational science is this: "the real sciences are about mental contents — which stand for things. Logic, on the other hand, is about mental contents that stand for mental contents."16

- Unity of Science. The unity of a science is based on neither its subject or object. First, the unity of a subject does not make a unity of science. Each branch of philosophy, for example, metaphysics or logic, is not one habit of the mind but an ordered group of habits. Since these habits are expressed by written propositions, a science can also be called a related collection of propositions. In this sense, Ockham spoke of Aristotle’s book of Metaphysics as the science of metaphysics: The unity of a science, therefore, is that of an ordered whole, like the unity of an army or city.

Since a science is a collection of many truths or propositions, it is not limited to one subject. Scientific propositions may have different subjects. Some metaphysical propositions, for example, have being for their subject, whereas others have God as their subject. Both views can be justified. Among all the subjects of metaphysics God is the primary subject as far as primacy of perfection is concerned, but being is the primary subject as regards primacy of predication. Consequently, metaphysics does not have numerically one subject. As there is no king of the whole world, so nothing is the subject of the whole of metaphysics. Each part of metaphysics has its own subject, just as each kingdom has its own ruler.17

Neither is the unity of a science based on the unity of its object, for each science has many objects. The objects of both rational and real sciences are the propositions it contains. "Every science, whether it be real or rational, is concerned only with propositions, as with objects known, for only propositions are known."18 Ockham did not imply that science has no reference to reality. The terms of propositions of real science stand for individual things existing outside the mind, whereas terms of logical propositions stand for concepts in the mind. Terms and propositions substituting for realities are the proper objects of real sciences which treat of the real world only indirectly and improperly.


III. Philosophy and Theology


Working within the framework of faith and reason, Ockham correlatively developed his ideas in the real sciences of philosophy and (revealed) theology. Although its propositions can be true and certain, theology cannot be a strict science, since it rests upon faith and authority rather than upon evidence.19 In another sense, both philosophy and theology are sciences as ordered mental habits expressed by a systematic collection of propositions. While theology is methodologically distinct from philosophy and concerns some subjects unknown to the metaphysician and conducive to salvation, for example, the Trinity and Incarnation, they are ordered to each other as a whole, similar to men in the unity of an army or city, and can treat of the same truths.20


IV. Simplicity of Explanation


In his demand for rigorous scientific thinking, Ockham passionately practiced a simplicity of explanation. This principle of economy, sometimes called "Ockham’s Razor," is often stated by him in the form: "Plurality is not to be posited without necessity,"21 and sometimes: "What can be explained by the assumption of fewer things is vainly explained by the assumption of more things."22 The formulation, "Entities must not be multiplied without necessity," does not seem to have been used by Ockham. He used the principle of parsimony to eliminate pseudo-explanatory entities according to the criterion that "we must not affirm something is necessarily required for the explanation of an effect, if we are not led to this by a reason proceeding either from a truth known by itself or from an experience that is certain."23 For Ockham, the sufficient reason for the truth of a statement is either the observation of a fact, or immediate self-evidence, or divine revelation, or a deduction from these. In view of these criteria, he wielded his methodological razor in sharp critical analysis.




- Scotus. Like Scotus, whose lectures he perhaps heard, Ockham believed that the reconstruction of the Augustinian tradition by the incorporation of Aristotelian ideas required a strict scientific approach. Heir to myriad sources of information in the writings of Anselm, Averroes, Avicenna, Bonaventure, and Aquinas, he was thoroughly convinced that a scientific procedure more rigorous than that employed by Scotus was necessary for a complete critical investigation of the problems of knowledge and reality.

- Logicians: Aristotle and the Scholastics. To achieve a radical reconstruction of Augustinian thought, Ockham adapted Aristotelian logic as the tool of his critique. In this adaptation he relied on Peter of Spain’s (later Pope John XXI) Summulae logicales which opened Aristotelian logic to new considerations of terms, signs, and suppositions,24 and on William of Sherwood’s treatise on syncategorematic terms. The distinctive feature of Peter and William’s logic was its use of the supposition of terms in formulating the syntactical and semantical properties of cognitive language. Ockham, undoubtedly influenced by this logic of terms, considerably refined the technical equipment of his predecessors. "In his Summa Logicae Ockham systematized the contributions of his predecessors in a reformulation of the whole content of Aristotelian logic on semantical foundations of a purely extensional character."25

Peter of Spain extolled dialectic as the art of arts and the science of sciences. By "dialectic," Peter meant probable reasoning. Some other thirteenth-century logicians shared this tendency to focus on probable reasoning as distinct from demonstrative science, on the one hand, and sophistical reasoning, on the other. Undoubtedly, Ockham was influenced by the preceding logicians’ emphasis on dialectical or syllogistic reasoning leading to probable conclusions. However, he went further than his predecessors in his penchant for regarding arguments in philosophy — as distinct from logic — as probable rather than demonstrative arguments.

- Nominalists. For an effective use of logic, Ockham believed it was necessary to reconstruct the foundation of universal concepts employed in logical and scientific thinking. Already in motion was an anti-realist movement by Durandus, Peter Aureoli, and Henry of Harclay to emphasize the foundation of universals in the mind rather than in individual things. Ockham climaxed that movement with a complete break from the realisms of Aquinas and Scotus, and concluded from the Aristotelian truth that only individuals exist that universality belongs solely to concepts and names, thereby instituting a new terminist or nominalist logic. Ockham adopted a nominalism along the lines of Roscelin of Compigne and Abelard to purify Aristotelian logic of the Neoplatonic corruptions which, for example, in Peter of Spain assumed that a universal term stood for a universal thing.

- Augustinian and Aristotelian Heritage. With the foundation of philosophy restructured in terms of nominalism, Ockham reexamined the superstructure of cognition and metaphysics. To guarantee a solid foundation and a simple superstructure, Ockham applied the principle of economy — "a plurality is not to be posited without necessity" (a common dictum of the scholastics and traceable back to Aristotle) — in a new way to strengthen the Augustinian lines of his system, namely intuition, the individual, and the will. He revised Scotus’ analysis of cognition into intuition and abstraction: in view of his Augustinian conviction of the primacy of divine causality, he believed intuition of a nonexistent is possible, and in view of his nominalism he limited abstraction to forming universal concepts.

By reinterpreting the Aristotelian metaphysics of being, the categories, matter and form, causality, and univocity in a radically nominalistic and empirical framework, Ockham was able to reconstruct anew the Augustinian tradition of the primacy of divine power and freedom, and the absolute dependence of creatures on God. In this way he endeavored to rectify the Aristotelian theories which failed to recognize the liberty and omnipotence of God.

The emotional repercussions of Ockham’s personal history and circumstances are evident in his polemical and political writings. In the academic atmosphere of Oxford, Ockham appears as the cold logician and calm philosopher, whereas in his exile at Munich, his teaching career cut short and the ban of excommunication on his head, he is the impassioned political and ecclesiastical controversialist. In both situations, Ockham showed himself an independent, original, and critical thinker, clear in his convictions and principles, and ready to apply them courageously, systematically, and logically in both the theoretical and practical arena.




Ockham responded to the problems of knowledge and reality by methodically developing his themes in the different areas of philosophy.


Theory of Knowledge


Ockham developed his theory of knowledge to meet the epistemological demands of science. He agreed with Aristotle that science is concerned with universal propositions. For example, the mind assents to the universal proposition that the whole is greater than the part, when it grasps the meaning of the terms. But for Ockham such scientific knowledge is not simply a priori in the sense of being a development of innate principles. For scientific propositions to be objective, they must be grounded in reality which, according to Aristotle, consists only of individuals. To validate scientific knowledge, Ockham has to account for both the universal and individual poles of knowledge.

Furthermore, Ockham recognized, outside the limited field of scientific knowledge, there are many statements that are true, evident, and even necessary, and therefore known with certainty. How does the mind arrive at them?

Ockham’s explanation followed the lead of Scotus in constructing a theory of knowledge on two basic modes of cognition: "The one may be called intuitive, the other abstractive cognition."26 The former mode belongs to the Augustinian tradition and the latter to the Aristotelian deposit of reason.


I. Intuition


Human cognition starts with the immediate experience of singular facts, either sensible or intelligible objects, whether outside or within the mind. "And therefore, just as the knowledge of sensible facts that is obtained from experience . . . begins with the senses, . . . so in general the scientific knowledge of these purely intelligible facts of experience begins with an intellective intuition of these intelligible facts."27 Intuitive knowledge is the immediate apprehension of existing things without any concept as a medium between things and the act of apprehending.

Following the Augustinian tradition, Ockham recognized that man directly experiences his mental states of understanding and willing without any previous sense perception.28 Natural knowledge, therefore originates from two sources: intuition of external sensible objects and intuition of psychological activity. This intuition is the basis for a self-evident existential statement that the contingent thing which is experienced exists, is present, and has such and such a condition of inhering or not inhering (accident or substance), of nearness or distance, and other concrete features. Caused by an individual thing and by no other thing, an intuition contains its own guarantee.

Even if the existential judgment concerns an object of sense, it is based on an intellectual intuitive cognition of an object. Although the intellect cannot intuit a sensible object without the help of sensation — at least in the natural order — the primary intellectual awareness relates to the sense-object as immediately as sensory cognition. Thus Ockham continued the Augustinian doctrine of the certitude of judgments regarding immediately given facts by grounding them in the intuition of singular things. "Intuitive cognition of a thing is cognition that enables us to know whether the thing exists or does not exist, in such a way that, if the thing exists, then the intellect immediately judges that it exists and evidently knows that it exists."29 The guarantee of such concrete judgments is the evidence presented by intuition.

- Intuition of Nonexistents. While it is evident that there cannot be intuition without a knowing subject, it is not at all clear whether intuitive cognition can take place without the existing object itself or its causality. With only the intellect present, it seems impossible to have intuition. However, as a Christian, Ockham believed in God’s omnipotence which as first cause can produce everything that a secondary cause can effect. "Intuitive cognition of a non-existent object is possible by divine power."30

Since God can supply the causality of a secondary cause and cooperate with the intellect to produce intuition, no existing object is necessary. God can collaborate in this effect, even if the object known is far away or inaccessible to direct contact with the intellect. For example, God could produce immediately in the organs of vision all those psycho-physical conditions which are naturally produced by the light of the stars. Since the act of seeing stars is distinct from the stars themselves, divine omnipotence could annihilate the stars and conserve the visual act with the object.

In stating that intuition can know an object which does not exist, Ockham has in mind an object which, though not existing in fact, can exist. But is it not a contradiction to speak of an intuition of something which does not exist? As a Christian theologian, Ockham believed that God has immediate cognition of everything, not only all that exists, but also all that could exist, but does not. If such knowledge is possible to God, it cannot involve a contradiction. An object which "does not contain a manifest contradiction"31 and hence is not pure nothingness, is a possible existent which can be intuited by the human intellect with the help of God.

Ockham excludes a contradiction not only from the object in itself but also from the very act of intuiting. "God cannot cause in us such knowledge through which there evidently appears to be a thing present to us when it is absent, because this includes a contradiction."32 God cannot cause a contradictory situation of evident knowledge that a thing is present when it is absent. Something cannot be both present and absent in the evident knowledge of intuition.


II. Abstraction


How can an intuited individual thing give rise to universal knowledge? To answer this question, Ockham analyzed the Aristotelian theory of abstraction. The mind also "abstracts from existence and nonexistence"33 to focus solely on the object itself. Since this knowledge does not imply the actual existence of the object here and now, it cannot be grounds for asserting the existential judgment, "This thing exists." Without a preceding intuition, abstractive cognition by itself does not suffice to make evident an existential judgment concerning contingent things. Although abstractive cognition prescinds from the object’s actuality or nonactuality, it is not universal knowledge. Since intuitive and abstractive cognition result from the causal cooperation of intellect and object, both represent real objects outside or inside the mind. Ockham, therefore, is a realist in his theory of knowledge.

- Universal concept. Intuition combines with abstraction to effect a concept. The crucial question for Ockham is how the concept becomes universal. The abstractive cognition is stored in the memory as habitual knowledge and generalized as a universal concept by way of comparison with other similar abstractive cognitions to represent, not just one, but many similar individuals. Thus, the universal "is a sign naturally predicable of many things, . . ."34 Nothing in the real world corresponds to the universality of a concept; "A universal is nothing other than a content of the mind; and therefore no substance outside the mind and no accident outside the mind is such a universal."35

Ockham argued against the existence of universals in various ways. If universals exist, they must be individual, for only singular things really exist; but it is a contradiction for something actually existing to be both individual and universal. Furthermore, if there were a common reality existing at the same time in two members of a species, the annihilation of one individual thing would involve the destruction of another individual thing. However, for example, one man can be annihilated by God without any other man being annihilated or destroyed. Therefore, there is not anything in common to both, because (if there were) it would be annihilated, and consequently no other man would retain his essential nature. The essence of an individual man is not affected by God’s creation or annihilation of another man.

With no universals in reality, what guarantee does the intellect have that its universal concepts provide objective knowledge of reality as it is with individual natures? Because of its origin in abstraction from intuited individual things, and because of the similarity between the individuals, the concept is common to all individuals of the same kind and hence predicable of them.36 Individuals, for example, Plato and Socrates, are similar not in the sense of sharing in a common reality, but in the sense that they agree with each other in the likeness of their individual natures. On this basis, universal concepts are said to represent individual realities. Whereas universality exists wholly within the mind as a sufficiently generalized abstractive cognition, only individuality and the similarity of singular natures exist outside the mind as the objective basis of universal concepts.

Ockham was not as sure about the nature of a universal concept in the mind. At first he considered the universal concept (for example, "man" or "animal" in the proposition "man is an animal") as something differing from the act of thinking of which it is an object with no psychical or physical reality other than that of thought-object in the mind."37 because the concept is merely mentally imaged, Ockham called it a "fictum" in the sense, not of a pure fiction, but of a logical "picture" constructed from the interaction of the object and cognition and hence truly representing the object. Peter Aureoli, Ockham’s contemporary, also held the "fictum" theory.

However, it appears that Ockham eventually gave up the "fictum" theory for what may be called the "intellection" theory, "according to which a concept is the same as the act of knowing."38 According to this view, the universal concept is a psychical entity which is identical with the very act of intellection. Since there are no universals to be drawn from individual sensible things, Ockham applied his principle of economy to get rid of the apparatus of abstracting intelligible likenesses (species intelligibiles). Immediately caused by the object and the intellect working together as two part-causes, the concept represents the object, and consequently can function as a predicate in a mental proposition.




Having investigated the mind’s universal concepts as the material needed for the various sciences. Ockham inquired into the logical arrangement of these notions to obtain truth and to organize them into a body. Since logic teaches one how to order concepts in the right way, it is a practical science, it is a tool of scientific work. Following Aristotle’s Organon, he divided the field of formal logic into the three classical parts: terms, propositions and reasoning.39 Ockham’s logic, like all medieval logic, treats mainly of spoken sentences which he distinguished from mental and written sentences.


I. Terms


The elements of propositions are terms. "A term is simply one of the parts into which a proposition is directly divided."40 It signifies an object to the mind. Nouns, for instance, are instituted by man to represent objects and to substitute as names for things in discourse. Language, for Ockham, is a system of conventional signs which depend on concepts. Since concepts are produced, not by the activity of artificiality instituting languages, but by the natural interaction of object and intellect, they are said to be natural signs to which the forms correspond. Words for an individual thing vary in different languages, for example, "man" in English and "homme" in French, but the concept or logical significance of the term is the same. However, both word and concept, properly speaking, directly signify tho same object.41

- Division of Terms. Categorematic and Syncategorematic. In his analysis of propositions, Ockham distinguished formal and material elements. In the proposition "every man is not white," the material elements, "man" and "white," are categeorematic terms, and the formal characteristics, "every," "is," and "not," are syncategorermatic terms (called "constants" by modern logicians). Whereas, the former terms naturally or conventionally signify definite objects, the latter have meaning only within the context of categorematic terms.42 The main subject of logic is syncategorematic terms which make inferences possible.

- Absolute and Connotative Terms. Categorematic terms are basically distinguished into absolute and connotative terms. Absolute terms, such as "man," "horse," and "intellection" directly signify an object. "A connotative name, however, . . . signifies something primarily and something else secondarily."43 A connotative term not only directly signifies an object, but indirectly stands for something else. For example, in the proposition "This table is quantitative," the term "quantitative" which immediately signifies "table" connotes or indicates that such a body has parts distinct from each other. Whereas absolute terms result from abstraction based on intuition and are susceptible of a real definition in answer to the question "What is this thing?", connotative terms are the outcome of a combination of concepts and are nominally definable in response to the question, "What is meant by this term?"

- First and Second Impositions. Ockham further analyzed terms into first and second imposition. The act of imposing a name on an object can take place on the first level of using terms, or on the second level of speaking about terms and signifying "only a conventional sign."44 As regards the spoken or written language, words of first imposition, as "man," "intention," and "universal," are assigned the task of signifying; and words of second imposition, as "substantive," "adjective," and "conjugation," refer to qualifications of language. The latter words, which always signify the former, are the main interest of the grammarian.

- First and Second Intentions. The distinction between first and second intentions concerns concepts. Concepts of first intentions such as "man" and "white" signify objects that are not signs;45 corresponding to this first level are words of first imposition. Concepts of second intentions such as "universal" and "species" are signs predicated of first intentions, as when it is said "man" and "horse" are species; correlative to this level are words of second imposition. In Ockham’s view, the projection of universals into reality arose from the logical mistake of construing terms of second intention as term of first intention and supposing, for example, that what is signified by the term "man" is some reality in individuals.


II. Supposition


Ockham refined and simplified the theory of supposition introduced by earlier logicians. Supposition "is a property belonging to a term, but only when used in a proposition."46

- Personal, Simple, Material. In the statement "the man is running," the term "man" stands for a definite individual. This is an instance of personal supposition "when a term stands for what it signifies and is used in its significative function."47 However, in the case of simple supposition the term itself becomes a subject of discourse and does not exercise a significative function. For instance, in the statement "man is a species," the concept "man" represents, not a man in reality, but simply the concept itself. Rejecting the earlier terminist logicians who had construed a simple supposition as tho use of a term for the universal supposed to exist in individuals, Ockham regarded simple supposition as the use of a term for the concept expressed by it. If the term as the subject of discourse is a word in "material" supposition, for example, in the sentence "`man’ has three letters," the sense is that the term "man," not as species or rational animal, but as word has three letters.

The importance of this distinction can be shown in dealing with the problem of whether a real science, such as physics, deals with physical objects in the extramental world or with propositions. In Ockham’s view, the term "science" is a second intention, since it is predicated of propositions or of a system of propositions. However, most of the propositions themselves are composed of first intentions.

- Determinate and Common Supposition. Ockham developed a logic of predication by distinguishing a personal supposition into determinate and common. The inference from an affirmative proposition such as "some man is white" to its singularized form "This man is white," (and so on for other individuals signified by the subjects) is valid. "There is determinate supposition when it is possible to make the logical descent to singulars by a disjunctive proposition."48 In a common, distributive, confused supposition, the logical descent from a universal proposition to singularized propositions is joined by the conjunction "and," as in this instance, "Every man is mortal; therefore this man is mortal and that man is mortal" (and so on for every individual man). The inference from a singular proposition to a more general statement is a process of ascent.49

- Ontological Foundation. Ockham’s analysis of the absolute and connotative terms of first intention unfolds the ontological foundation of his logic. For Ockham, the terms Aristotle grouped under the category of primary substance as signifying what they essentially are, are absolute terms that signify individuals when used in propositions with personal supposition. The concrete terms of the categories of accident which signify "this quality," or "so big," or "in such a place," are connotative terms that directly refer to the substance and obliquely to some contingent factual condition. For instance, the term "round" directly pertains to the sun and indirectly to its shape.

- Logical Truth. Ockham utilized his theory of supposition to clarify Aristotle’s view that a proposition is true when that which is said to be is. The term "truth" and "falsity" are second intentions predicable of propositions which they signify and for which they can stand. Ockham restates Aristotle with greater precision when he says that for a proposition to be true "it is sufficient and necessary that subject and predicate should stand for (have supposition for) the same thing."50 For example, the statement "Socrates is white" is true if there really is one individual signified by the terms "Socrates" and "white" even though the terms themselves and the notions associated with them are not identical. The terms "true" and "false" are connotative terms that directly signify propositions and connote that subject and predicate stand for the same state of affairs.51


III. Consequences


With other medieval logicians, Ockham viewed the syllogism as a special type of inference within the general theory of consequences (consequentiae) which can be understood as conditional propositions expressed in the general form: If A is, then B is. Its antecedent and the consequent may be either simple or compound propositions. In his analysis of conditional propositions, Ockham formulated many rules of inference which are well-known theorems of propositional calculus in modern logic. For example, "From truth falsity never follows";52 when the antecedent is true and the consequent is false, the inference is not valid.




Within the framework of his logic and theory of knowledge, Ockham developed his metaphysics by a critique of traditional metaphysical doctrines.


I. Being


Ockham followed Aristotle in describing metaphysics as a real science whose "subject is being . . . , not nevertheless in word but in concept."54 It deals with the concept of being in general, which is formed after the intuition of existing things. In the first sense, "the noun `being’ is associated with a concept which is common to all things and can be predicated of all things."55 Being as such, the most common concept predicable about things, "stands only for a concept in the mind, not for substance nor accident,"56 nor a common nature in things. There is no "being as such" in the extramental world; there are only beings.

In the second sense, the term "being" stands for all individual things, both substance and accidents, ranging from inanimate bodies, plants, animals, human beings and angels, to God — in fine, all actually existing individuals, or everything to which it is not repugnant to be in the actual order of things. Since every one of these individuals is conceived of as a "being," then "being" can be predicated of every one of them. The concept of being can be predicated about everything that exists or can exist.

As "the adequate object of our intellect," being is most common, and univocal to everything per se intelligible."57 For that reason, being is a natural object of the human intellect inasmuch as this "power is naturally inclined towards it"58 without attaining every element of the object’s content. Through intuition of singular existents, the intellect first abstracts "the concept of being"59 and in a progressive process of generalizing abstraction forms the universal concept of being as such.

- Substance. Ockham conceived Aristotle’s primary substance as the individual subject. However, "no external corporeal substance can be naturally apprehended in itself, by us, however it may be with respect to the intellect itself or any substance which is of the essence of the knower."60 For example, from the observation of fire, we know that it is fire; yet, in reality, we do not know fire in itself but only the accidents of fire. Known only as the substratum of sensible qualities, corporeal "substance is therefore understood in connotative and negative concepts, such as `being which subsists by itself,’ `being, which is not in something else,’ `being which is a subject of all accidents.’"61

- Essence and Existence. Since the term ‘being’ denotes everything that exists or can exist in the universe, it necessarily refers by its very meaning to actual existence. In view of this notion of being, Ockham found it as meaningless as Scotus to distinguish between essence and existence in a real thing: "Existence is not a thing different from the essence of a thing."62 While differing grammatically, both terms signify exactly the same individual reality. As means "essence" and "existence" signify the same individual grammatically and logically. "The words ‘thing’ and ‘to be’ (esse) signify one and the same thing, but the one in the manner of a noun and the other in the manner of a verb."63

While admitting that the noun "essence" cannot simply be substituted for the verb "to be" for obvious grammatical reasons, Ockham was sensitive to any encroachment of grammatical distinctions on metaphysics. The grammatical distinction between essence and existence cannot properly be taken as a basis for distinguishing them as distinct things; they are the same thing. Thus, he could maintain that a creature is truly its own essence and existence, and nevertheless allow for an ultimate distinction between God who of himself is necessary, infinite, and uncaused, and a creature which is not from itself, contingent, finite and caused.

Ockham understood Boethius’ famous distinction between what a thing is (quod est) and that by which a thing is (quo est) as a real distinction in a creature: "that which a creature is and that in virtue of which a creature is are simply distinct, just as God and a creature are distinct."64 A creature, as that which is, really differs from God by which he is, whereas there is nothing different from God in virtue of which God is.

- Act and Potency. Such is the case also with the supposed distinction in things between potential and actual being. To say that something exists potentially does not mean that "something which is not in the universe, but can exist in the universe, is truly a being."65 This involves a distinction between two kinds of statements, assertoric and de possibili, and not between things denoted by the terms of statements. In Ockham’s view, most of the traditional metaphysical doctrines represent confusions of logical and physical concepts, or of ways of signifying things and the things signified.

Since only concrete singular things exist outside the mind, there are no principles really (essence and existence in Aquinas) or formally (common nature and individual in Scotus) distinct, save those entities which are separate or separable.


II. Univocity


Ockham agreed with Scotus that the general concept of being is univocal. Since every individual is conceived as a being, the concept of being can be univocally predicated of everything that exists or can exist. Unable to intuit God or to have a simple proper concept of him, the human mind needs to abstract from immediately known creatures to acquire a common concept predicable of him and other beings. For instance, the notions "being" and "first" abstracted from intuited things can be combined to form the composite proper concept "first being."66 The elements of such a concept are predicable in exactly the same sense of God and creatures, linking experience to the unintuited Divinity. If the term "being" were not univocal, such that one and the same meaning did not correspond to that term, there would be no link joining the experience of creatures to the unexperienced God; the outcome could be agnosticism in regard to God.

Ockham distinguished three kinds of univocity. First, a univocal concept may be common to a number of things which are perfectly alike, for example, the concept of man common to individual men. Second, a univocal concept may be common to a number of things which are alike in one way and unlike in another. For instance, man and donkey are alike in being animals and having similar matter, though their specific forms differ. Third, the term "univocal" denotes a concept common to many things which have no likeness, either substantial or accidental."67 It is in this sense that a concept common to God and creatures is univocal, since they are completely dissimilar in reality. What is common to God and creatures in the conceptual order radically differs in the real order. The univocity of the term "being" and of others used in metaphysics, imply no real similarity between God and creatures: ". . . in God and in creatures there is nothing at all intrinsic or extrinsic, which is of the same kind."68 As a melody can be the same though each note is different when played in a different key, the one concept of being can be univocally applied to completely dissimilar beings, as infinite being and finite being. The term "being" (also the term "substance") is predicated of every individual, not simply as qualifying some other thing, for example, as the term "white" is applied in the manner of a quality (in quale) to a subject, but in its own right as a "quiddity" (in quid). This theory of univocity enabled Ockham to lay the foundation of a natural theology without falling into pantheism or agnosticism.

Ockham saw no need of analogy to avoid pantheism and agnosticism. If analogy is understood in the third sense mentioned above, then the univocal concept of being may be called "analogous." However, recourse to the theory of analogy to avoid pantheism is unnecessary, since being as such which is common to God and creatures is not a real thing in which both participate but rather a concept. From the viewpoint of reality, God and creatures are radically different beings, and the concepts corresponding to these individuals also have different significations. In this case, since the concept of God is not the same as the concept of creature, the term "being" should be predicated, not univocally, but equivocally, of them. This would lead to agnosticism. For Ockham, predication is either univocal or equivocal. There is no room for analogy.69


III. Causality


Ockham retained the fourfold Aristotelian division into formal, material, final and efficient causes, and reduced the exemplar to cause in a metaphorical sense.70 In general cause is a positive entity distinct from what is caused by it. Efficient cause is that which, having been posited, the effect follows and, having been removed (all other circumstances remaining the same). the effect does not follow. "An efficient cause," Ockham wrote, "is defined as that whose existence or presence is followed by something."71 This definition shows an empirical tendency on the part of Ockham to interpret causal relation as regular sequence.

Knowledge of a causal relation depends on experience. Ockham was quite emphatic on this point. He insisted that knowledge of a given thing having a cause does not mean one knows what particular thing is the cause. No amount of a priori deduction can establish that one individual thing is the cause of another individual. Only intuitive cognition of each of the two things and experience of their sequence can disclose whether one is the cause of the other.

In the experiential verification of a causal relation it must be shown that when one definite thing is present another thing follows, or when the former is absent the latter does not follow. For example, "it is proved that fire is the cause of heat, since when fire is there and all other things (all other possible causal factors) have been removed, heat follows in a heatable object which has been brought near the fire."72

Ockham confined knowledge of causal relations to experience because, in view of God’s absolute power and freedom, he found no inherent reason in contingent things necessarily relating them; their causal relations, therefore, appear as regular sequences which experience encounters as matter of fact. Ockham’s empirical view of causality goes hand in hand with his theological outlook. His preference for scientific induction over a priori deduction in the determination of causal relations derives from the demands of his theology rather than from the exigencies of purely physical science in which he showed comparatively little interest.

In the case of two really distinct things, for example, fire and burning, Ockham held that God could cause one without the other. "Although burning always follows the contact of fire with an inflammable object, this does not exclude the possibility that its cause is not the fire. It may be that God has so ordained things that whenever fire is compresent with the object, he himself is the cause of the burning."73 Since God can supply for the causality of any secondary cause, one cannot strictly prove that a given effect is caused by a secondary cause and not by God alone.74 However, Ockham did not deny the validity of causal argumentation. On the contrary, he used causal arguments to reason from the characteristics of a given effect to a cause. Since God created things in such a way that a certain order results, one can empirically study that invariable succession and predict that the causal relations experienced in the past will be experienced in the future, even though God’s absolute power could intervene in the world.


Natural Theology


With a theory of univocity linking creatures and God, Ockham would develop a natural theology on the basis of his metaphysics. At the outset, Ockham encountered the question of whether God is the term of human cognition.


I. Knowledge of God


In the tradition of medieval thought, Ockham affirmed that the human intellect cannot naturally intuit, and consequently cannot abstractively know God as he is in himself.75 The primary object of the human mind is the nature of material things. Since human understanding does not have the divine essence as its immediate object, it "cannot know God in this life in a concept that is simple and proper to Him,"75 just as a man born blind cannot have a proper concept of color. Hence, the proposition, "God exists" is not self-evident to man in this life. This being so, is it possible to have certain natural knowledge of God from creatures?

However, God "can be conceived by us in some common concept predicable of him and others."77 For example, from the experience of other things, the intellect is able "to abstract the concept of wisdom from created wisdom" and "imperfection from the wisdom of the creature,"78 to form a complex concept of wisdom which is common to God and creatures. These connotative terms principally and quidditatively signify God and secondarily refer to the different created perfections.

The distinct composite concepts which man has of God, a single being, indicate that he immediately knows, not the divine essence, but rather concepts of God, mental representations of the Divine. None of these mental constructs is a simple proper concept adequately mirroring the divine essence. The human mind can attain a nominal representation (quid nominis) but not the reality (quid rei) of God. Although the human mind "cannot know in themselves either the unity of God . . . or his infinite power or the divine goodness or perfection," its propositions signifying these attributes, nonetheless, have meaning. Thus theology is a real science of "concepts which . . . we use in propositions to stand for God,"79 and theological propositions are objective in the sense of referring to the divine reality.

Unaided natural reason can strictly demonstrate with utmost certainty from evident promises only a few conclusions about God. Other inferences can be made by way of persuasive (probable) or dialectical argument from premises not evident but accepted by all, or at least by all acute and trained minds. The conclusion may be certain, but not evident. One can be certain who one’s parents are without the fact itself being evident to that person.


II. Proof of God’s Existence


- Argument from production. For Ockham, tho proposition that God exists can be strictly demonstrated. He criticized Duns Scotus’ form of the proof from efficient causality as not sufficiently conclusive.80 In the case of accidentally ordered causes, for example, a series of men, each of whom successively begets a son, it is difficult, if not impossible, to prove that there cannot be an infinite regress in causes of the same kind with one able to exist without the other. Furthermore, one is not logically bound to postulate coexistence in time of all causes essentially belonging to the same series: "not everything which mediately or immediately produces a thing coexists with the thing produced. Therefore, in the order of productive beings we could go on ad infinitum,"81 without conclusively affirming a first efficient cause.

- Proof from Conservation. By shifting his perspective from origination to conservation, Ockham found that the difficulty of infinite regress could be overcome and Scotus’ argument from essentially ordered causes be made more cogent. In a series of conserving causes, wherein one thing keeps another in existence, and the former itself is being maintained by something else, and so on, it follows ex hypothesi that the whole series must be simultaneously existing. Since it is "reasonable enough" to suppose that an infinite number of contemporaneous conserving causes is impossible, there must be a primary conserver of the world here and now.82 Ockham’s criticism of Scotus, therefore, is directed more against the actual form than against the main principle of his proof.

- Reasoning from Finality. Ockham rejected as insufficient Scotus’ proof of God’s existence from final causality. The fact that natural agents act uniformly does not warrant any valid conclusion other than that they move by natural necessity. It is meaningless to say they move for an end, unless one presupposes the existence of God who created their natures and thereby determined inanimate things to act as they do. But this reasoning assumes precisely what needs to be proved.83 As to intelligent agents, it is evident that their own wills move them, but it cannot be shown that all wills are moved by the perfect good, God.84 With no adequate evidence of an immanent teleological order in the universe, Ockham believed he could not convincingly infer the existence of God as its final cause.


III. Attributes


Ockham recognized the possibility of demonstrating certain divine attributes. For instance, as highest being, God must have both intellect and will. Since every being is good, and God is a being, it can be concluded that God is good. "Good," the middle term of this syllogism, is a concept common to God and creatures, and hence univocally predicable of both. Since the connotative term, "good" is not simply synonymous with the term "being" and tautological, it calls to mind a relation to the will, thereby increasing one’s knowledge of God. In the proposition "God is good, the term "good" has personal supposition because it stands for God himself and by the same token signifies him. All the divine attributes are, properly speaking, terms which substitute for, and signify, God.

- One. Like Moses Maimonides, Ockham denied that one can strictly demonstrate that there is one God. Although the proof of God’s existence discloses that he is "that than which nothing is more noble and more perfect,"85 it does not strictly imply that God excels anything equal to him. Since other worlds besides our own are possible, it is consequently conceivable that there are other primary conserving causes. Then it is a question of proving that one conserver is the cause of all others. With no demonstrative argument for God’s unicity, Ockham turned to persuasive reasoning that seems to be adopted from Duns Scotus. If two gods of equal perfection were possible, then why cannot three, or even an infinity of such gods exist. But since what is possible is also necessary to God, an infinity of gods must exist. An infinity of separate beings, however, is a contradiction and hence inadmissible. By implication, it follows therefore that not more than one God can and does exist.

- Infinity and Omnipotence. Having rejected the strict demonstration of an absolutely primary cause, Ockham logically denied strict proof of an infinite and omnipotent being as creator of all things. Since "every effect producible by God is finite," and "effects together are finite also," then "by their efficiency the infinity of God cannot be proved."86 Since there is a proportion between cause and effect, finite effects would seem to require merely finite causes.

If human reason cannot demonstrate the impossibility of a being equal to God, then by implication it cannot prove that the primary conserver is all-powerful and not limited. Any attempt to demonstrate such attributes in a syllogism assumes that the notions "infinite" and "omnipotent" can be used as middle terms predicable of the concept of God as the absolutely supreme being. Such a fallacy begs the question by assuming there is such a being to which infinity must be attributed.87 Human reason, at most, can give only probable or persuasive arguments for the infinity and omnipotence of God.

Nonetheless, Ockham developed his whole philosophy in view of the divine omnipotence which he professed within the framework of faith. "That God is the mediate or immediate cause of all things . . . cannot be demonstrated, yet I argue persuasively for it on the basis of authority and reason."88 On the premise that God who is infinite will and infinite power, can do anything that does not involve a contradiction (which is none other than absolute nonentity),89 anything that is possible, Ockham inferred that whatever God produces by means of secondary created causes, he can produce and conserve immediately without their aid. For example, God can produce and conserve an accident without its substance, matter without form, and vice versa.90

- Omniscience. Human reason cannot strictly prove that God knows other things beside himself. Demonstration would have to rest mainly on God’s universal causality. But it can neither be proven by means of the principle of causality that a cause knows its immediate effect, nor demonstrated that God is the immediate cause of all things. Probable arguments for God’s knowing some things other than himself are inconclusive. However, it cannot be demonstrated that God knows nothing other than himself, because it cannot be proved that every act of cognition depends on its object.91 Ockham, nevertheless, affirmed the omniscience of God as an article of faith.

- Ideas. If God knows all things, does this mean that he needs ideas to know creatures? On the one hand, according to Ockham, Scotus’ view that the divine ideas have their own being distinct from that of the divine essence, implies many beings in God to the detriment of his absolute simplicity. On the other, Aquinas’ position that the divine ideas are identical with the being of God, is equivalent to saying there can be only one divine idea. Applying his principle of economy, Ockham himself found it unnecessary to postulate such ideas in the being of God to explain either his production or knowledge of creatures.

Infinite in knowledge and power, God has no need of intermediary ideas in knowing and creating other beings.92 Just because man uses ideas or concepts to signify something about God does not justify his projecting ideas into the Godhead. This is a confusion of the linguistic or conceptual and real orders, with words and concepts being taken for realities. In Ockham’s opinion, the theory of ideas in God is simply an anthropomorphic invention. However, perhaps out of respect for the traditional Augustinian acceptance of the theory of ideas, Ockham was not prepared to abandon the theory altogether.

The connotative term "idea" "can be predicated of the creature itself, but not directly of the divine "knowing agent nor of the knowledge, since neither the knowledge nor the knower is an idea or pattern."93 It connotes indirectly the divine knowledge or knower. The ideas are not subjective realities in God. "The ideas are in Him only objectively, that is, as certain things which are known by him, for the ideas are things themselves which are producible by God."94 Creatures as known by God are really the ideas. The patterns or exemplars in view of which God knows and creates actual existents are nothing more than the creature as known from eternity by God.

Since individual things alone are producible outside (the mind) and no others,"95 it follows that there are divine ideas of individuals but not of universal genera and species nor of negations, privations, evil, and guilt, which cannot be actually distinct existents. What is the sense of postulating ideas of universals in God when there is no reality corresponding to them? According to Ockham‘s principle of parsimony, there is no reason for postulating ideas in God which are distinct from creatures themselves, whether the ideas are understood as real or mental relations. Absolutely independent, God bears no real relation to creatures. If the idea were a mental relation, it could not be the exemplar of the creature, just as a purely mental construct or being of reason (eus rationis) such as genus or species cannot be the exemplar of a real being.

Inasmuch as God can produce an infinity of creatures, the number of ideas must be unlimited. Aquinas and Scotus spoke as though the distinction of ideas in God were prior to the production of creatures. Before creation, the ideas have no positive reality but are simply "nonbeings" in the divine mind.96 This negative status of the divine ideas respects God’s absolute simplicity and at the same time guarantees his knowledge of things other than himself.

Ockham’s talk of ideas may give one the impression he contradicted his previous rejection of the theory of ideas. However, although he retained the language of the theory of ideas, his interpretation of it differs so radically from its traditional meaning that he seemed to reject the older understanding of the theory for a completely new explanation. His interpretation of ideas as identified with creatures is consistent with his philosophical principle that only individuals exist while universals are unreal and with his theological safeguarding of divine omnipotence from the restrictions of Greek essentialism. His identification of ideas with creatures enabled him to observe that Plato acted rightly in neither identifying the ideas with God nor placing them in the divine mind.

- Divine Liberty. God’s liberty, though not strictly demonstrable, can be affirmed with persuasive reason. The fact of contingency in the world presupposes that God is a free cause which cannot be hindered and equally regards an infinite number of things in the same way.97 "But because of the limitlessness of volition (the divine will) is free as regards opposite objects."98 Since the divine will "intends the object contingently in such a way that at the same instant it could intend the opposite object,"99 it can produce one effect and not the other.

- Knowledge of Future Contingents. Human reason cannot strictly demonstrate that God knows events depending on free wills for their actuality. Since "a future contingent fact simply depends on a free power and hence is not true in itself,"100 what will happen or what will not happen cannot be known as true. Neither statement taken by itself, namely, "This will happen," or "this will not happen" can be known to be true. One can simply state as true the disjunctive proposition, "Either this will happen or this will not happen."

Motivated by faith, however, Ockham held "without any doubt that God knows all future contingent facts evidently and with certainty. The manner in which he knows them, I, however, do not know."101 Ockham reasoned that as the human intellect can know contingent propositions from an intuition of their terms given in experience (for example, "the sun is shining."), "so the divine essence itself is an intuitive cognition by which are known not only necessary truth and contingent truth about a present fact, but also which side of a contradiction will be true and which will be false."102 For example, God knows not only whether I shall choose to walk or not to walk tomorrow, he also knows which alternative is true and which false. Implied in Ockham’s position, in opposition to Aristotle, is his rejection of any propositions that are neither true nor false. This shows that Ockham did not admit an exception to the principle of excluded middle. Appealing to faith, Ockham noted that God could reveal affirmative propositions about future contingent events to the prophets, because he knew the truth of such propositions.

- Distinction of Attributes. The divine attributes, as terms, differ from each other as distinct concepts or words, but as regards the reality signified by these terms they are in every sense identical with each other and with God’s absolutely simple essence.103 "In God there is no distinction between essence and will, nor between intellect and will."104 While agreeing with Aquinas that the divine attributes differ by a distinction of reason,105 Ockham rejected Aquinas and Scotus’ views of a foundation in the divine being for the distinction of man’s concepts of God, and affirmed that concepts such as wisdom and goodness, which stand for the one, simple, divine reality, have exactly the same meaning in God. They differ in meaning only insofar as they connote created wisdom and goodness which are really distinct qualities in creatures.106




I. Induction


The real science of nature treats of concepts which signify changeable things. It "is about mental contents which are common" to movable and corruptible things and "which stand precisely for such things in many propositions."107 It inductively starts from the more known, and through observation, experience and reasoning ascends from effects to causes. The passage from singular to universal propositions affirmed for all possible cases is justified by the analytically evident principle that all individuals of specifically similar nature (eiusdem rationis) act or react in a similar manner to similar conditions. Since God can produce an effect without its natural cause, the application of this rule is valid only within the general hypothesis of the common course of nature.


II. Contingency


Ockham viewed the world against the background of divine omnipotence and freedom. The world is ordered in the sense that certain evils are readied by particular means. To explain this order, Scotus distinguished between God’s choice of the end and then his choice of the means. Ockham, however, objected to any anthropomorphic projection of human ways of acting into the Divine. "It does not seem to be well said that God wills the end before that which is (ordered) to the end, because there is not (in God) such a priority of acts."108

In addition, such language of priority and posteriority seems to impair the utter contingency of the world-order. The choice of both end and means is completely contingent. In view of the divine omnipotence and infinite freedom, Ockham conceived all changeable things as radically contingent in their created structure; to be a creature means to depend entirely on God’s free will. Whatever stability the world-order possesses is completely dependent on God’s free decision.109 Infinitely wise and good, God’s freedom is not arbitrary; his freedom is wise and good, and his wisdom and goodness are unconditionally free. Bound only by what is a contradiction, which in reality means nonbeing, his power and freedom are encompassed by nothing real; they are really boundless.


III. Categories


- Substance and Quality. In accord with the principle of economy, Ockham reduced the Aristotelian categories to substance and quality, as "white," and "hot." Whereas these two categories are absolute terms signifying distinct entities, the other categories are connotative terms denoting either a substance or a quality and stand for something else. Thus the latter categories are in no way different from the individual contingent bodies they modify. Since "quantity signifies substance, connoting that it has part distant from part,"110 it is "the very substance of a thing."111 Likewise, motion, place, and time are in no way different from the bodies concerned.112

- Relations. Ockham’s general tendency to analyze the world into contingent individuals without any necessary connections is sharply reflected in his treatment of relations. For Ockham, the only real distinction independent of the mind is the one between separate or separable entities. Thus a relation is really distinct from the terms of the relation if it is separate or separable from them. But it is absurd to hold that a relation is really distinct from its foundation. If it were, the relation of paternity, for example, could be produced by God and conferred on someone who had never generated a child. To compare Plato and Aristotle as philosophers, it is unnecessary to postulate a third entity, a relation of similarity, in addition to the individual or "absolute" substances and qualities.

Ockham did not identify a relation with its foundation. "But I say that a relation is not the foundation but only an ‘intention’ or concept in the soul, signifying several absolute things."113 A relation is a name or concept denoting the comparison of substances or qualities with each other. This means that outside the mind, the order of the universe, for example, has no reality distinct from the existing parts of the universe.

Ockham’s view of relation had the effect of rendering null and void the common teaching in the Middle Ages that the creature has a real relation of dependence to God, although God’s relation to the creature is only a mental relation. This common way of speaking, for Ockham, simply means that God and creatures are different kinds of beings. There is no need of postulating a mysterious entity called an essential relation of dependence between creatures and God.

In this case, the relation of dependence, is analyzable in reality, into two existents, creatures and God, and simply means that the latter individuals cannot exist without the former who produces and conserves them. Ockham is willing to speak of a real relation of creatures to God but only in the sense that what is produced and conserved, and what produces and conserves, actually exists, without any third entity being added to the creature.114

- Motion. The various kinds of movement — qualitative alteration, quantitative change, and local motion — are not positive entities distinct from permanent things in reality. It is a false supposition to think that for distinct abstract terms or words such as "motion," "succession," and "simultaneity," there corresponds a distinct thing. When a body gradually acquires a qualitative form, it is superfluous to postulate something other than the thing and the quality gained. It is obvious that quantitative change involves nothing more than "permanent things" increasing or decreasing in parts.

To be moved locally "is first to have one place, and afterwards, without any other thing being postulated, to have another place . . . And consequently the whole nature of motion can be saved by this without anything else but the fact that a body is successively in distinct places and is not at rest in any of them."115 It suffices to postulate a body and its place to explain local motion.

- Place and Time. Ockham’s razor also shaved down the Aristotelian categories of place and time. The statement that a body is in a place can mislead one into thinking that, because the words "body" and "place" are distinct terms, the realities signified by the names are really distinct. On the contrary, place is identical with the surface or surfaces of a body or bodies. Time is not a thing distinct from a moving body. "Primarily and principally ‘time’ signifies the same as ‘motion,’ although it connotes . . . an act of the soul, by which it (the soul or mind) knows the before and after of that motion."116 Time denotes no distinct thing outside the soul beyond what motion signifies. For Ockham, time and motion are simply distinguished as terms by the mind.

Ockham allowed no other absolute entity to creep into his simplified world unless it was necessary for a full explanation of the facts. For example, he rejected both the theory of impetus according to which the stone receives the quality of impetus, and the old theory according to which the projected object is kept in motion by the surrounding air. It is sufficient to assume that the movement imparted by the hand to the stone is identical with the moving body and remains until it is impeded. "Such motion as occurs through the separation of movable object from its first projecting body, the moving agent is the very thing that is moved . . . , so that this mover and the thing it moves are absolutely indistinguishable."117


IV. World-view


Ockham accepted the world-system commonly held by thinkers in the Middle Ages. With Thomas Aquinas and Duns Scotus, he believed that the beginning of the finite world in time cannot be demonstrated: "God could have made the world from eternity, since no contradiction seems to follow from this."118 As God is absolutely powerful and free to create the world from eternity, so "God could make a better world" than the present one.119 Everything was made for man who was created for God. At the center of the universe is the earth, surrounded by the spheres of the planets and stars. All creatures are divided into two groups, the spiritual and the material.


V. Matter and Form


Ockham adopted Aristotle’s hylomorphic theory with the exception of the notion of privation which he eliminated as superfluous. Matter and forms are "the only two principles of any generation."120 Primary matter is not pure potentiality but a positive entity which is the same in all composite physical bodies, heavenly as well as terrestrial.121 "Matter is really actual by itself and it can by no means be reduced to a mere potentiality," although it is "always in potentiality with reference to the form which it lacks."122 Since the individual is nothing other than the form of the whole (forma totius), the union of matter and form, no principle of individuation is required apart from its efficient cause.




I. Soul


In view of his demands for strict demonstration, Ockham criticized the inadequacy of a number of psychological proofs advanced by his predecessors. Natural reason would undoubtedly suppose that one’s acts of understanding and willing, which are intuitively cognized, are acts of his substantial form. However, since they are experienced as acts of the form of the body, there is no compelling reason for assuming that form to be incorruptible and separable from the body rather than an extended and corruptible form. If, however, intellective soul is understood as an immaterial and incorruptible form, "it cannot be evidently known by reason or experience that such a (immaterial and incorruptible) form exists in us."123 Nor can it be strictly proved that the acts of understanding one experiences are "proper to such a substance . . . in us."124 Even if one could demonstrate that these experienced acts of understanding belong to an immaterial substance, it would not follow "that such a soul is a form of the body . . . These three things are only matters of belief."125

- Plurality of Forms. While accepting on faith the existence of an incorruptible form in a human being, Ockham hesitated to say that this form directly determines matter. The corruptibility of the human body presupposes "another form in addition to the intellectual soul, namely a sensitive form, in which a natural agent can act by way of corruption and production."126 The matter of the human body supports the sensitive form which determines it (the matter). The sensitive form is extended in such a way that its various parts perfect the different sensory organs, such as sight and hearing.

The ambivalent experience of desiring a thing with the sensitive appetite and turning away from it with the rational will indicates a real difference between the sensitive and intellective souls, though this distinction is difficult to prove. Ockham’s problem in holding a real distinction between the sensitive and rational souls in man is that it makes it harder to safeguard the unity of man than does Scotus’ theory of formal distinction. For Ockham, a real distinction can exist only between things which are separate or separable, at least by divine power. If, however, the sensitive form is really separable from man’s rational form and from his body, it is difficult to preserve the unity of man.

In brutes and men, the sensitive soul is distinct from the form of corporeity which explains the numerical identity of a dead body with the individual’s formerly living body. Within a theological context, the form of corporeity accounts for the numerical identify of Christ’s dead body with his living body. The intellectual, sensitive, and corporeal forms are united in the individual: "There is only one total being of man, but several partial beings."127 Thus Ockham rejected Aquinas’ theory of one form in favor of the Augustinian tradition of a plurality of forms.

II. Faculties


The plurality of forms does not imply that the rational soul is really (Thomas Aquinas) or formally (Duns Scotus) distinct from its faculties. Unextended and spiritual, the rational soul cannot have parts or distinct faculties. Intellect and will appear as really distinct when they are taken as connotative terms which signify the different acts of understanding and willing. However, from the viewpoint of the one rational soul producing the acts of understanding and willing, intellect and will are really identical as partial causes in their one eliciting principle; they are nothing but the "one substance of the soul."128

Similarly, the sensitive powers, though distinct accidental dispositions in the various sense-organs, are identical in the sensitive form as the one source effecting the various acts of sensation.129 The activities of this one simple soul can be stabilized by habits which as additional forms are accidental and really distinct from the soul.130

- Intellect. In accord with his principle of parsimony, Ockham saw no need of sensible and intelligible likeness to explain knowledge which involves simply an act of knowing and individual realities.131 Chimera and nonbeing are nothing but the mind’s act of knowing to which nothing corresponds in reality.132 If intelligible likenesses were first known, knowledge would stop at them and one would never know whether they resemble reality.133

There is no compelling reason for distinguishing the active intellect from the passive intellect. "The agent and possible intellects are completely the same in reality and in principle. Nevertheless, these names or concepts connote different aspects,"134 the former connoting the soul as actively producing knowledge and the latter designating the same soul as passively receiving knowledge. With no essence to be abstracted from individual things, abstraction is simply an activity in which the intellect on experiencing one or more things elicits an indistinct act of knowing and produces a universal concept.135

- Will. Ockham followed the Franciscan tradition of Bonaventure and Scotus in upholding the priority of the will over the intellect. "With reference to what their names signify, the will may be called superior to the intellect, because the act of loving, designated by the word ‘will,’ is superior to the act of understanding, designated by the word ‘intellect.’"136 What necessarily moves the intellect in the act of understanding is freely chosen or rejected by the will. In the ultimate analysis, "a true rather than a false proposition is formed, an affirmative rather than a negative, . . . because the will wants to form the one and not the other."137 The intensity of conatus and the attention in cognition depend on the act of the will.

- Freedom. Freedom is one of the chief characteristics of a rational being. Intuition, not a priori reasoning, reveals that man is the cause of free acts: "It can, however, be known evidently through experience, that is, through the fact that every man experiences that however much his reason dictates something, his will can will or not will it."138 Freedom is "the power whereby I am able indifferently and contingently to posit an effect, so that I am able to cause and not to cause the same effect without any change being made in this power."139 Furthermore, blame and praise attributed to responsible persons indicates the reality of their freedom. In complete possession of itself, the will enjoys self-determination, the power to act or not to act even if all the necessary requirements to an act are given. "The will is properly a rational power,"140 which has a capacity for "contrary effects, because it can cause the love of something or hate."141

Ockham found it difficult to explain how repeated acts of the sensitive appetite can result in the formation of habits in a free power like the will. Experience shows that the will is more inclined not to choose an object causing pain in the sensitive appetite, even though the intellect present it with the option of not choosing the object. On the other hand, pleasure in the sensitive appetite is not the cause of the inclination of the will which is free to choose the opposite. No matter how much the will is inclined towards a habit formed by the sensitive appetite’s indulgence in a certain direction, the will, even though with difficulty, remains free to act against that habit.142

Liberty of the will is the basis of moral goodness, and responsibility. The seat of morality is in the will, "because every act other than the act of will, which is in the power of the will, is only good in such manner that it can be a bad act, because it can be done for an evil end and from an evil intention."143 Since every action, other than the act of willing itself, can be performed by reason of natural causes and not freely, it could be caused in man by God alone instead of by his will, and consequently, in itself be neither virtuous nor vicious, except by denomination from the act of the will.144

The will, according to Ockham, does not necessarily seek happiness, the last end. "The will contingently and freely . . . enjoys the ultimate end shown in a universal," or particular way, "because it is able to love and not love happiness."145 However, since natural reason does not know that the enjoyment of God as the last end is possible and since there "is not in our will an inclination intensively to the infinite good,"146 man does not necessarily will the enjoyment of God.147 Even if faith testifies to its possibility, man can still will or not will to enjoy God, as experience reveals. Vis-à-vis the intellect’s judgment, the will remains free. It does not necessarily desire even perfect happiness in general. Though "the will does not necessarily conform to the judgment of reason, it can conform with the judgment of reason, whether that judgment be right or erroneous";148 for example, if the intellect judges that perfect happiness is impossible and incompatible with human existence, the will can consent to that judgment.


III. Person


The plurality of forms and faculties is unified in the human person which as "an intellectual and complete nature is neither supported by anything else nor is able, as part, to form with another thing one being."149 The individual subject or suppositum is "a complete being, incommunicable by identity, incapable of inhering in anything, and not supported by anything."150 As complete, the human person can neither be a generic, specific, or numerical part of an individual being, not identical with another individual, nor an accident inhering in another, nor assumed by another individual. Though the rational form constitutes a human being as an intellectual supposit (suppositum intellectuale) distinct from other kinds of subjectivity, it alone is not the total being of man. Only the person embraces the whole man.151




Ockham developed his ethical notions against the background of his views of God’s absolute freedom and omnipotence and man’s contingent relation to his creator.


I. Moral Goodness


The term "moral" refers to "human acts which are subject . . . to the power of the will according to the natural dictate of reason and according to other circumstances."152 The term "goodness" signifies that something is as it ought to be. The will determines what a thing or action should be. A pen is good, for instance, if it is made as it should be in view of the function for which it has been willed. Because all creatures have been caused by God in conformity with his will, they are good.153

Likewise, a human act is morally good, not by conformity to an eternal law, but insofar as it is commanded by the omnipotent and absolutely free will of God. "With him (God) a thing becomes right solely for the reason that he wants it to be so."154 Because what God wills is good and what he forbids is evil, it is by definition impossible for him to order something bad. As the supreme ethical norm, God’s will should be obeyed. To put it more exactly, the one free God of wisdom, love, power, and mercy is the supreme rule of ethics. Man is morally obliged to follow the laws freely laid down for him by God’s will.155


II. Obligation


For Ockham, the ontological foundation of the moral order is man’s dependence on God, as creature on creator. Whereas God who is unconditionally free falls under no obligation, man whose freedom is contingent and created is subject to moral obligation. Man is morally obliged to will what God commands and not to will what God forbids him. Thus the content of the moral law derives from divine precept. "Evil is nothing else than doing something when one is under an obligation to do the opposite."156


III. Basis of Morality


Ockham viewed the moral law in its existence and content as completely contingent on God’s omnipotence and unbounded freedom. This is a radical departure from the positions of Thomas Aquinas and Scotus, who, in spite of their differences, agreed that the natural law in its immutable essence is founded on the universal idea of man in the divine mind; consequently, both recognized that there are human acts which are forbidden because they are intrinsically evil. For Ockham, however, the ultimate norm of morality is, not the divine ideas (which are reducible to the creatures they signify), but God’s omnipotent, free will.

It is possible for God’s absolute power, viewed logically apart from all his other attributes, to do everything that involves no contradiction. "Everything which does not include a contradiction nor a moral evil can come from God."157 Not ruled by an eternal law and nobody’s debtor, God is bound (if this can be called an obligation) only by the impossibility of a contradiction which, in reality is nonbeing. To be bound by nonbeing is equivalent to not being bound at all. This, in effect, means that God is absolutely free to command or to forbid whatever he wills. Ockham did not hesitate to draw the logical consequences of his position.

The first consequence is diametrically opposed to Aquinas and Scotus’ view that intrinsically good actions are commanded because they are good and intrinsically evil acts are forbidden because they are evil. For Ockham, however, no acts are good unless willed by God, nor evil unless forbidden by him.

Second, as omnipotent, God can produce as total cause what he can effect as a partial cause. The command of a man that others hate God is concurred in by God as universal and primary cause. "Thus he can be the total cause of an act of hatred of God, and that without any moral malice."158 God’s absolute power can command that a person should hate him or at least not love him.159 By the very fact that God wills something, it is right for it to be done. There would be no sin either in God since he is under no obligation or in man who is not obliged to avoid something beyond his power. Such a situation seems to give rise to an antinomy in Ockham’s ethics. If God commanded a man to hate him, his obedience to that order would be an act of love God. Hence, the fulfillment of God’s command to hate him seems to be an ethical impossibility.

What is at work here is the principle of noncontradiction. God cannot order a man to love and hate him at the same time, which is equivalent to saying that his power can command everything except not to obey him. On recognizing that a certain command is God’s will, man is bound to obey. To do God’s will or, equivalently, to love God, is the highest moral law. "The act by which God is loved above all and for His own sake" is a necessarily virtuous act and "the first of all good acts."160

According to the third consequence of God’s absolute power over the moral order, what is now forbidden regarding creatures can be commanded and what is now commanded can be forbidden. For example, stealing and committing adultery, forbidden by God in the present order, can be commanded as good by God. "They may even be meritoriously performed by man if they fall under divine precept, just as now their opposites, as a matter of fact, fall under the divine precept." Underlying Ockham’s reasoning is his denial of any absolutely necessary connection between loving a creature and loving God. The present way of loving a creature is only contingently ordered to loving God by God’s will. Between love of God and the illicit love of a creature, there is only an extrinsic repugnance arising from God’s actual prohibition. What God prohibits now, he can command if he so desires.161


IV. Right Reason


Right reason is also a norm of morality. "It can be said that every right is in conformity with right reason."162 For an act to be perfectly virtuous, it must not only agree with, but be commanded by right reason which Aristotle includes in the definition of virtue. "For to elicit an act in conformity with right reason is to will what is prescribed by right reason on account of its being so prescribed."163 An act motivated merely for the sake of pleasure would not be virtuous. In emphasizing right reason as the proper motivation, Ockham was following Aristotle who had insisted that for an act to be perfectly virtuous, it must be done not simply because the righteous person would do it, but because it is the right thing to do.

Anchored in reason are certain universal principles which regulate every human act; for example, "everything honest should be done, every good should be loved, everything dictated by right reason should be done."164 Particular practical judgments of conscience are grounded in these general ethical principles. Even if mistaken a man is obliged to will what is prescribed by reason. "A created will which follows an invincibly erroneous conscience is a right will; for the divine will wills that it should follow its reason when this reason is not blameworthy." To act against an invincibly erroneous conscience is to sin.165 The dictates of conscience are expressions of God’s free decision that it should act according to given norms.

In freely legislating, God has laid down a particular moral code obliging all men. While retaining his absolute power (potentia absoluta) to command whatever he desires, God’s ordained power (potentia ordinata) has actually established a definite moral code. All people can discover this natural law which they are obliged to follow. Although God is not constantly changing his laws, he not only could have established another moral order, but could at any time command what he has actually forbidden.166 Ockham’s intention, therefore, is not to undermine the moral order or to promote immorality, but to make unmistakably clear the primacy of God’s absolute power and liberty.




In his political and polemical writings, Ockham inveighed against tyrannical power and the deprivation of natural rights on the basis of right reason.167


I. Natural Rights


Ockham’s political writings were occasioned by disputes involving the Papacy. In criticizing Pope John XXII’s pronouncements on evangelical poverty as heretical and erroneous and in defending his Franciscan confreres, Ockham analyzed natural rights as a legitimate power in conformity with right reason. Man, for example, enjoys a natural God-given right to property, the legitimate power "of disposing of the goods of the earth which right reason would dictate . . . not only to live, but also to live well."168 The right of private property restricts the right of common possession for the due management and procurement of things which are necessary for a good life.169 Willed by God, the natural right of private property comes from the natural law anterior to human convention, and consequently is violable by no earthly power against a man’s will. Although the State can regulate the way property is to be transferred, it cannot legitimately deprive a man of the exercise of the right of private property, still less of the right itself unless there is fault on his part or some reasonable cause,170 for example, his criminal use of property against the common good.

Ockham distinguished different kinds of natural rights. First, there are natural rights which are valid under certain conditions until a contrary convention is established; for example, the right of the Roman people to elect their bishop may be ceded to the cardinals.171 Second, there are natural rights operative in the state of humanity before the Fall and conditional on a state of perfection no longer existing. Third, there are natural rights sharing in the immutability of moral precepts, such as the right of private property and the right to life.

However, these rights are not quite the same. Whereas the right to life cannot be renounced, for example, by starving oneself to death, without sinning, the right of private property can be relinquished without going contrary to the moral law. It is not necessary for every individual to exercise the right of private property in order to fulfill the moral precept of right reason to appropriate temporal goods. For a just and reasonable cause, the Franciscans voluntarily renounce all rights to property.172

Pope John XXII, however, emphatically insisted that it was unjust to use temporal things without having a right to them, and hence that the Franciscans were entitled to use temporal things like food and clothing only because they have a right over them. The common view among the Franciscans, on the contrary was that they could legitimately use those things whose ownership was voluntarily renounced. Ockham defended this common view by maintaining that the Franciscans gave up the right of using (usus juris) as distinguished from that right over their substance, and possessed simply a factual use (usua facti) deriving from mere revocable permission to use the things of another.173 Their use of temporal things was permitted by the Holy See who has the right of ownership and right to use things. Ockham’s concept of evangelical poverty after the example of Christ and the Apostles was declared heretical by John XXII.


II. Church and State


In 1323 Pope John XXII denounced the election of Ludwig of Bavaria, as Holy Roman Emperor by claiming that papal confirmation was required. On the occasion of this dispute, Ockham strongly supported the independence of the State against encroachments by the Church. "In appointing Saint Peter to the head and sovereign of all the faithful, Christ assigned to his power certain limits which he was not to overstep."174 The absolute power of a pope contradicts the liberty of the holy gospel according to which men are free in Christ and also right reason which opposes placing unrestricted power in the hands of one human being.175

Like most medieval thinkers, Ockham insisted that the spiritual and temporal spheres must be clearly distinguished. "By God not only is papal power instituted, but also many others, that is, the secular powers are instituted by Him."176 As the spiritual power of the pope is directly from God absolutely independent in its own realm, so the secular dominion of the emperor and the jurisdiction of all legitimate sovereigns, originating immediately from God through the people or their electors choosing the ruler, is also autonomous in its own domain and governed by natural law for the common benefit. The task of the State, besides preventing crimes, is "to give to each one his rights and to save them, to make the necessary and just laws, to institute the subordinate judges and officials, (to decide) which handicrafts (artes) are to be exercised and by whom, to prescribe acts of all the virtues, and many other things."177

Ockham protested against the tendency of certain popes to arrogate to themselves the position and rights of universal temporal monarchs. "Whenever, therefore, the pope, in case of necessity, meddles in temporal affairs, he is thrusting his sickle in alien crops, unless he be entrusted with power to do so by the emperor or by some other person."178 Neither pope nor sovereign should interfere in the other’s affairs over which he has no jurisdiction. "Although the emperor is supreme ruler of the multitude of the faithful, nevertheless he is not supreme ruler of the person of the pope in temporal affairs on account of reverence for the office which the pope exercises, and because in spiritual matters he is superior to the emperor."179 Ockham expressed a common medieval outlook when he insisted that there should be a proper balance between the sword of secular power and the staff of religious authority for peace between State and Church.180 With a common source in God, the distinct spiritual and temporal powers should collaborate for the common good.181


III. People and Ruler


All people enjoy an inviolable natural right to set up a government endowed with jurisdiction.182 The ruler may be elected either directly or indirectly through human law according to which legitimate authority is transmitted to a successor, as in the case of a hereditary monarchy. Thus while the right of instituting government and the right of private property come immediately from God by natural law, the actual setting up of a government and the appropriation of temporal things is usually the act of man and of human law.183 His power derived from God, the ruler cannot be arbitrarily deposed by the people except in cases specified by positive or natural law, for instance, unfitness or danger to the common good.184


IV. Universal Monarchy


Ockham envisaged a commonwealth of all nations as a political ideal: "Therefore, he is not truly zealous for the common good, who does not desire and work, as far as he can in his station, for the whole world to be subject to one monarch."185 As there is one pope presiding in the spiritual sphere, so there should be one monarch in the temporal order.




Ockham’s philosophy comes into historical focus by viewing it in retrospect, conspectus and prospect.


Retrospect: Modern Way


Nominalism. In the second half of the fourteenth century, Ockham’s philosophy was called the "modern way" in contrast to the "old way" of Thomism and Scotism. An independent, daring and vigorous thinker, Ockham initiated a new way of thinking that is characterized by nominalism, empiricism, and voluntarism. In opposition to the realists of the old school, Ockham attributed universality only to names and inaugurated a way of thought that conquered the greater part of Europe.186

In conceiving the universality of being as only a term, Ockham’s nominalism or terminism limited the scope of metaphysical knowledge so as to shift the focus of philosophy from metaphysics to logic. Ockham’s nominalism represents "an extreme economy of ontological commitment in which abstract or intentional extralinguistic entities are systematically eliminated by a logical analysis of language."187 In view of this transition, it is not surprising that Ockham valued highly the certitude he found in the truth of logic above the probability he frequently arrived at in his conclusions about God and man. Ockham’s fame lies in his founding the nominalist movement.

- Empiricism. Ockham’s nominalism implies an empirical view of knowledge and reality. With no universal to be abstracted from reality (as Aquinas and Scotus believed) and only individuals existing and relating in a contingent manner, human reason cannot abstract necessary connections from the nature of things, but must observe things in experience to discover the structures and function of the actually existing world. No a priori deduction can discover the completely contingent order of the world; it must be empirically examined for what it is in actual fact. Experience verifies that an individual thing is the cause of another. On the basis of this new radical empiricism, Ockham rewove the whole fabric of philosophy.

- Voluntarism. Ockham’s empiricism is grounded in his voluntarism. The need to observe individual contingent things arises from the fact that they completely depend on God’s absolutely powerful and free will. Ockham carried the primacy of the divine will over intelligence found in Bonaventure and Scotus to its utmost limits in order to overcome Greek necessitarianism. To all intents and purposes, he broke with the old Augustinian tradition of orienting God’s will towards the divine ideas and originated a new way of viewing God as unconditionally free.188




I. Original Synthesis


Ockham’s bold new way of thinking in a nominalistic, empirical, voluntaristic framework enabled the "Venerable Inceptor" systematically to construct an original philosophical synthesis by renewing the logic of Aristotle.


II. Logic


"Ockham’s principal gift to his generation was his new system of logic . . ., a technique of great subtlety resembling in some respects the symbolic logic of our own day."189 He surpassed other scholastics in his careful analysis of signification and supposition to elucidate a semantic notion of truth. He applied the theory of supposition with a rigor, consistency, and thoroughness hitherto unknown to the medieval discussion of philosophical and theological problems. Ockham excelled in the analysis of modal syllogisms and consequences which he expressed in theorems that anticipated the so-called De Morgan laws.190

In line with Ockham’s logic, Walter Burleigh in his main work, On the Purity of the Art of Logic (De puritate artis logicae), and Albert of Saxony in his treatise, A Very Useful Logic (Perutilis Logica) developed the theory of consequences. These studies in the structure of inferences and their elements constitute a notable development in the history of formal logic.


III. Knowledge


Ockham executed a tour de force in shifting the center of philosophical gravity from metaphysics to logic by transferring the foundation of universality from reality to the mind. By no means is Ockham a pure subjectivist, for the universal concepts are grounded in things and their similarities as individuals, and the propositions of a real science signify singular things. In view of this relationship of concepts to reality, Boehner calls him "a realistic conceptualist."191 However, his razor-sharp exclusion of the abstraction of the nature of sensible things from his theory of knowledge had the effect of restricting the capacity of human reason, and limiting many propositions about God, the soul and the world to at best a high probability. Nevertheless, in a certain sense, Ockham went beyond Thomas Aquinas in guaranteeing the objectivity and certainty of scientific knowledge by holding with Scotus an intellectual intuition of individual realities.192

Besides, Ockham, the theologian, worked within the traditional framework of faith seeking understanding. If understanding could at most reach probability, Ockham’s faith remained unshaken in its certitude concerning God and the soul. The Augustinian tendency (reaffirmed by Bonaventure) to stress the limitation and weakness of human reason found authentic expression and fulfillment in Ockham’s critical reduction of not a few scientific demonstrations to the level of probability. As a result, the close collaboration of faith and reason which worked so harmoniously in Bonaventure and Aquinas to acquire certitude appeared to break down into a new and looser association wherein (revealed) theological certitude was backed only by philosophical probabilities. In his conception of theology and philosophy as collections of mental habits or of propositions, Ockham contributed to the modern notion of science as an ordered body of knowledge. In addition, his preference for singulars rather than universals, intuition rather than abstraction, and induction rather than deduction, prepared the ground for a more scientific approach to reality, an empirical study of facts rather than an a priori deduction of conclusions.


IV. Metaphysics


With his penchant for logic, Ockham defined metaphysics as a real science of propositions signifying individual beings. This definition agrees with his nominalistic view of being — the object of metaphysics — as a universal term standing for individuals. To simplify explanations, he banished from metaphysics all Platonic ideas, and likewise the mitigated Platonism of Aristotle in which the essence precedes at least logically and naturally, though not in time, the individual. For Ockham essence as well as existence is equated with the individual. In his estimation, this simplification of metaphysics overcomes verbal difficulties and endless discussions about problems originating from grammar.

By understanding substance in connotative terms rather than general names, in descriptive phrases rather than proper names, the category of substance in Ockham tends to be "reduced to the referential function expressed in language by the phrase `thing such that . . .’ or by what is equivalent to the bound variable of quantification."193 Ockham’s conception of substance as the posited referent of the connotative predicates points towards John Locke’s "something I know not what" characterization of substance.

By restricting the application of being to its univocal predictability as a term, and limiting the consideration of (efficient) causality to a fact requiring experienced verification, it is not surprising that Ockham found it difficult to obtain certitude of any reality beyond intuited sense objects. If it cannot be established with certainty by any other way than by actual experience that X is the cause of Y, what certainty can there be that the world is caused by God who is not naturally experienced? Though Ockham anticipated the modern empirical philosopher, David Hume, in rejecting the a priori deduction of an effect from its cause and in basing knowledge of causal relations on experience alone, he is not skeptical of the objectivity of causation which he grounded in the uniformity of nature.194 Some historians interpret Ockham as a subverter of traditional metaphysics, but the fact is that his nominalistic metaphysics reconstructed past thought in an original synthesis that climaxed in conclusions about God.


V. God


In view of his strict notion of science, Ockham, for the most part, arrived at probable conclusions about God’s existence and attributes. He qualified his demonstration of the existence of a first efficient cause from conservation with the possibility that this first cause could be a heavenly body. However, the concept of a primary conserving cause is not all that is usually understood by the term "God." If the term "God" means the absolutely supreme, perfect, unique and infinite being — as Scotus understood the term — then Ockham did not think the existence of such a being could be strictly demonstrated by the philosopher. Faith is needed to be certain of the existence of a supreme and unique being in the fullest sense.

Ockham’s epistemological principles and strict concept of science made it extremely difficult for him to demonstrate with certitude in natural theology. His logic is ever at hand in his metaphysics and theological reasoning to remind him that the requirements of a demonstration are exacting and difficult to fulfill. In a strictly scientific metaphysical, Ockham wanted only demonstrative conclusions, and not convictions. This tendency in Ockhamism to reduce many philosophical conclusions to probability so lessened the enthusiasm of later Christian theologians for philosophy, that they turned to patristic theology which emphasized the reading and linguistic study of Scripture.

Ockham, however, was not a religious skeptic. On the contrary, intensely loyal to the Christian faith, he objected to demonstrating what cannot be proved and to packing (revealed) theology with pseudo explanations that blunted and obscured the articles of Christian belief. Motivated by belief in God’s absolute power and freedom, Ockham completely rejected the ancient metaphysics of essence which as divine ideas restricted God’s freedom and omnipotence, and as a common nature in things constituted them necessary in themselves and in their connections when all they are in reality is contingent. The core concept of God’s unconditional power and freedom gives inner cohesion to Ockham’s whole philosophical system.

Ockham’s concept of divine omnipotence and absolute freedom effects every aspect of his thought. Theologically, it meant that God can produce Y without any need of X as secondary cause. In Ockham’s world-view, this meant that all natural processes are contingent not only in the traditional Christian sense that God can miraculously intervene in the regularity of nature, but in the more radical sense that all uniform connections in nature have no inherent necessity and consequently are reducible to a successive existence of individual things. When it comes to verifying the causal relations of individual things, the regular sequences of nature, recourse must be made not to a priori deduction but to empirical experience. Even the present moral law — its obligatory force and content — completely depend on God’s all-inclusive power and liberty.


VI. Creatures


Ockham’s radically contingent world is composed of individual beings whose existence and order is a sheer fact without any metaphysical ground of common nature or necessary causal relations. With no matters of fact derivable from any a priori necessity, the world from strictly empirical observation appears simply as two categories, individual substances and qualities. Ockham wielded his razor or principle of economy to shave away entities whose independent existence is not demanded by experiential data or divine revelation. By rejecting essences which confer on nature a comparative stability and necessity, Ockham contributed to Western man’s quest for a substitute to traditional metaphysics in a scientific approach to the world.

Ockham’s view of the universe gave a definite impetus toward the growth of the empirical approach. For Ockham, the universe consists of "absolutes," namely, substances and qualities. They are "absolute" in the sense that they exist and can be understood without reference to other entities. If this is so, then an approach, such as that of Bonaventure, which focused on the way creatures mirror God, is unnecessary. Such an approach implies that creatures cannot be understood except as having a real relation to God. But if creatures are "absolutes," they can be investigated in and for themselves alone without any advertence to God. From such an approach, it follows that empirical science is an autonomous discipline.

Ockham’s inability to strictly prove the existence of God in the full sense of the term gave added impetus to the study of the world in itself without reference to God. While recognizing that Ockham, as a Christian theologian, never questioned the radical dependence of things on God, it seems legitimate in view of the aforementioned to regard his thought as a catalyst in the emerging "lay spirit," as Logarde does.

To simplify his explanation of the world, Ockham eliminated all distinctions (Scotus’ formal and Aquinas’ real distinctions) except those between separate or separable entities. His treatment of sensible qualities as distinct from substances, and of quantitative predicates as signifying nothing other than substances having parts outside of parts, is a step toward the modern view of corporeal substance as essentially extension with qualities as secondary.

Ockham’s application of his strict criteria of evidence to the physical doctrines of Aristotle showed that many principles accepted by the Stagirite as necessary and self-evident, are not evident. For Ockham, the arguments for the immateriality, ingenerability and incorruptibility of celestial bodies, and for the impossibility of a plurality of worlds and of action at a distance are inconclusive. His openness to the possibility of different theories equally capable of accounting for the facts helped create the intellectual atmosphere for later fourteenth-century philosophers to explore new physical theories, thereby laying the foundation for the scientific revolution of the seventeenth century.

- Man. Ockham remained faithful to the Franciscan tradition of a plurality of forms and a real identity of intellect and will. The unity of man, which appears prima facie to be weakened by the real distinction between the sensitive and rational souls, is upheld in the reaffirmation that only the whole individual man as a person actually exists. Since the terms "intellect" and "will," "active" and "passive," refer to the operations of the same person, the psychology of really distinct faculties is not evident or necessary.


VII. Ethics


Ockham’s ethical theory is positivistic in the sense that it derives moral goodness from God’s will. Ockham’s unconditional voluntarism in regard to God enabled him to break completely with the Thomistic and Scotistic notion of an immutable natural law grounded in the ideas of divine reason. If the present moral order depends solely on the divine choice and if there is no common, stable, necessary nature in individual things to be abstracted, how can man’s natural reason know what is actually commanded as good and forbidden as evil, unless it turns to faith in a revealed ethic? Unless God makes his will evident in revelation, it is difficult to see how human reason alone could be certain of a definite code of morality contingent solely on divine choice. It would seem that the most human reason could do is either dictate a set of hypothetical imperatives contingent on the present moral order or prescribe a provisional code of morality to suit present circumstances. If reason can discern some intelligible content in the present moral order apart from revelation, how can that content be dependent simply on the divine choice?

There seems to be an unresolved tension, on the one hand, in Ockham’s theological insistence on the absolute authority of the divine will in determining moral goodness and, on the other, in his Aristotelian emphasis on reason as the norm of morality for discerning what is right and what is wrong. How Ockham can be so emphatic in his authoritarian conception of morality and at the same time be so insistent on the necessity of right reason for virtuous action and natural rights grounded in an immutable moral law, is difficult to understand. Does it make real sense to speak of an immutable moral law in which the right of private property is rooted and to make that same law changeable by divine will? Ockham no doubt, would resolve this difficulty by grounding right reason and natural rights in the divine will. In other words, the ultimate and sufficient reason for following right reason and for recognizing natural rights is God’s will. This resolution, to all intents and purposes, makes no moral law absolutely immutable.


VIII. Politics


Although Ockham personally opposed the tyrannical exercise of papal power and sided with the Emperor, he developed his political thought within the traditional framework which clearly distinguished between the religious authority of the Church and the secular power of the State, and recognized basic rights of subjects in society. His rejection of the absolutism of papal and secular power conforms with his view that only God has absolute power and freedom, and that each individual exists with unique rights. Though Ockham’s dislike of arbitrary power and his insistence on law were by no means novel ideas, the manner in which he controverted the papacy was part of a revolutionary movement toward the consolidation of centralized national States completely independent of the Church.




I. Growth of Ockhamism


Despite the censures of Ockhamism at the Papal Court in Avignon and subsequent prohibitions against teaching it at Paris, it spread rapidly and flourished in the universities of Europe during the 14th and 15th centuries, rivaling in popularity Thomism and Scotism. An anonymous treatise De Principus Theologiae,195 about 1350, deduces the main tenets of Ockhamism from two principles: the omnipotence of God and Ockham’s razor. Of the many philosophers in the fourteenth century who developed Ockham’s basic principles in a more or less original way, the most important were John of Mirecourt and Nicholas of Autrecourt, both of whom taught at the University of Paris.

John of Mirecourt (fl. c. 1345) agreed with Ockham that, outside of faith, certainty can be attained by way either of the principle of noncontradiction or of experience. Strict demonstration from evident premises can be achieved on the basis of the principle of noncontradiction. For example, if God exists, he exists; if man exists, animal exists (for man is an animal). Absolute certainty about one’s own existence can also be achieved, for, as Augustine inferred, doubting one’s existence implies affirming it. However, experience of the external world is fallible inasmuch as God can miraculously cause the appearance of something not really existing. Like Ockham, Mirecourt conceived God’s absolute power and will as the cause of the moral law even to the point of being able to command man to hate him or his neighbor.

Nicholas of Autrecourt (fl. c. 1347) agreed with Ockham and Mirecourt that the principle of noncontradiction and experience are bases of certainty. In view of the primary law that contradictory propositions cannot be true at the same time, he proved the truth of what are today called analytic judgments with the predicate being contained in the notion of the subject (for example, the whole is greater than the part), and the truth of empirical judgments (for example, that I see red). Since it is impossible to detect any necessary causal connections in nature, it is impossible to infer the existence of one thing from the existence of another. The certainty deriving from a direct experience that one thing is the cause of another (for example, that fire heats an object close to it) lasts only as long as the sensible encounter after which it is only probable that the same effect will follow upon the cause. This empirical view of causality later earned for the author the title of the medieval David Hume.

In view of his notion of causality, Autrecourt denied that natural reason could demonstrate God’s existence from that of the world and relied upon faith for certainty concerning God. Likewise, to infer from the experience either of the qualities such as heat and color, or of acts of understanding and willing, the reality of substance is, at best, probable. Having undermined Aristotle’s physics by casting doubt on the reality of substance, Nicholas returned to ancient Greek atomism not only for its easy solutions to the problems of change, continuum, and the void, but also for its easy reconciliation with God’s causality. A universe composed of an infinite number of constantly moving atoms without necessary ties between them is readily subject to God’s power and free will.

Despite the condemnation of Nicholas of Autrecourt and John of Mirecourt by Pope Clement VI, Ockham’s terminist logic became prevalent not only at Paris and Oxford, but also at the universities of Heidelberg, Vienna, Erfurt, and Leipzig. The Collectorium of Gabriel Biel (d. 1495), which summarizes Ockham’s doctrines and fills in gaps left by the master, exercised considerable influence, especially in the German universities where he was read by Luther who claimed to belong to the Ockhamist sect.196

Nominalism, however, suffered the fate of most philosophical movements and declined, perhaps due to its "logic-chopping" and reserved attitude towards metaphysics. Drained of their energies by exaggerated logical refinements and subtlety, later nominalists contributed little to the fresh impetus received by philosophy at the time of the Renaissance.


II. Anticipations


Although not particularly interested in empirical science, Ockham did anticipate a key idea of the modern empirical method, namely that the only adequate ground for asserting a causal relation between two phenomena is the empirical observation of regular sequence. At Oxford the Ockhamist tradition of grammatical and logical analysis survived until far into the 17th century. Thomas Hobbes’ logic goes back to the nominalist version of the logic of terms. There are striking resemblances between the empiricism of Ockhamism and that of such philosophers as John locke and David Hume. From Ockham up to the "ordinary language" school of philosophy of the 20th century, one finds a steady series of warnings not to be misled by the use of abstract terms. Ockham’s logic of supposition, with its emphasis on functionality anticipated the approach of contemporary linguistic analysis.




1. See P. Boehner, "Introduction," Ockham: Philosophical Writings (New York: Thomas Nelson and Sons, 1962). pp. xi-xvi. Quotations will generally be from this edition by permission.

2. With few exceptions, Ockham’s works are available in 15th and 16th century editions and in facsimile reproductions, along with some recent publications. For a detailed description of these works and a list of spurious writings, see Boehner, op. cit., pp. iii-iix.

3. A critical edition of the philosophical and theological works under the title Guilleimi Ockham Opera omnia philosophica et theologica is being prepared under the direction of the Franciscan Institute at St. Bonaventure University, St. Bonaventure, N. Y.

4. Perihermeneias I was edited by P. Boehner, Traditio, 4 (1946), 320-335.

5. The new edition is by P. Boehner (St. Bonaventure, N.Y.: Franciscan Institute, 1951).

6. On the authenticity, nature, and relation of the last three works (5-7), see Boehner, "Three Sums of Logic attributed to William Ockham," Franciscan Studies, XI (1951), 173-193.

7. This is the main source for his theological and philosophical doctrines. It is called Ordinatio because Ockham "ordered" or prepared it for publication on the basis of his lecture notes. Boehner edited Question 1 of the Prologue, Paderborn, 1939; "B. I, d. 2, q. 8," The New Scholasticism, 16 (1942), 224-240.

8. The work is called Reportatio because it is a "report" of Ockham’s lectures. Boehner, "Reportatio, B. II, q. 14-15," Traditio, I (1943), 245-275.

9. Predestination, God’s Foreknowledge, and Future Contingents, trans. M.M. Adams and N. Kretzmann (New York: Appleton-Century-Crofts, 1969).

10. Three volumes of these treatises have appeared in a critical edition at Manchester University: Vol. 1, ed. J. G. Sikes, 1940; Vol. 2, ed. R.F. Bennett and H.S. Offler, 1963; Vol. 3, ed. H.S. Offler, 1956.

11. Guillelmi de Occam, Breviloquium de potestate papae, ed. L. Baudry (Paris: J. Vrin, 1937).

12. Ordinatio, d. III, q. 6.

13. Prologue to the Expositio super viii libros Physicorum. See D. Wehering, Theory of Demonstration according to William Ockham (St. Bonaventure, N.Y.: The Franciscan Institute, 1953).

14. Summa totius logicae, III, c. 2.

15. Quodlibeta, IV, q. 19.

16. Prologue to the Expositio super viii libros Physicorum.

17. Ibid.

18. Ord., d. I, q. 2, 4, M.

19. Ibid., Prologue, 7, E.

20. ". . . A conclusion that is not only specifically the same but also numerically the same can be proved in theology and in natural knowledge, provided that both [sciences] exist in the same intellect. For instance, the conclusions ‘God is wise,’ ‘God is good.’" Quodl., V, q. 1. See Ord., Prologue, q. 8, C; 1, F. See A. Maurer, "Ockham’s Conception of the Unity of Science," Medieval Studies, 20 (1958), 98-112.

21. Reportatio, II, q. 17, Q. See G. O’Hara, "Ockham’s Razor Today," Philosophical Studies," 12 (1963), 125-139.

22. See Tractatus De sacramento altaris, cap. 28 (Burlington, Iowa: T.B. Birch, 1930), p. 318. Also, Ord., d. 30, q. 1, E.

23. Rep., II, q. 150.

24. At the beginning of his work, Peter wrote that "dialectic is the art of arts and the science of sciences" which opens the way to the knowledge of the principles of all methods. Ed. I. Bockenski (Rome: Marietti, 1947), p. 1. Tracts VI-XII have been edited with an English translation by J.P. Mullally, Notre Dame, Ind., 1945. See P. Boehner, Medieval Logic (Chicago: University of Chicago Press, 1966).

25. E. Moody, "William of Ockham," Encyclopedia of Philosophy, 8 (New York: Macmillan Co. and Free Press, 1967), p. 310.

26. Prologue to the Ord., q. 1, N. See P. Boehner, "Notitia intuitiva of non-existents," Collected Articles on Ockham, ed. E. Buytaert (St. Bonaventure, N.Y.: The Franciscan Institute, 1958), pp. 268-300.

27. Ibid.

28. Ord., Prologue, I, HH; Quodl., I, q. 14.

29. Prologue to the Ord., q. 1, N.

30. Quodl., VI, q. 6.

31. Ibid.

32. Ibid., V, q. 5.

33. Prologue to the Ord., q. 1, N.

34. Summa totius logicae, I, c. 14.

35. Ibid.

36. Inasmuch as the similarity of concepts is founded in the agreement of every individual with the totality of individuals, Boehner prefers to call Ockham’s theory "realistic conceptualism." See "The Realistic Conceptualism of William Ockham," P. Boehner, Collected Articles on Ockham, pp. 156-174.

37. Ord., d. II, q. 8, prima redactio. In medieval terminology, the universal concept has no "subjective being" (esse subjectivum) but an "objective being" (esse objectivium).

38. Expositio super librum Perihermenias, 8.

39. See P. Boehner, Medieval Logic (Chicago: University of Chicago Press, 1966), pp. 80-83.

40. Summa of All Logic, I, c. 1, n. 1.

41. See P. Boehner, "Theory of Signification," Collected Articles of Ockham, pp. 201-232.

42. Summa of All Logic, I, c. 4, n. 3.

43. Ibid., I, c. 10, n. 4.

44. Ibid., I, c. 11, n. 5.

45. Ibid.

46. Ibid., I, c. 62. See G.B. Matthews, "Ockham’s Supposition Theory and Modern Logic," Philosophical Review, 73 (1964), 91-99. R. Price, "William of Ockham and Supposition Personalis," Franciscan Studies, 30 (1970), 131-140. J. Swiniarski, "A New Presentation of Ockham’s Theory of Supposition with an Evaluation of Some Contemporary Criticisms," Franciscan Studies, 30 (1970), 181-217.

47. Ibid., I, c. 63.

48. Ibid., I, c. 68.

49. See Boehner, "Theory of Supposition," Collected Articles on Ockham, pp. 232-253.

50. Summa of All Logic, II, c. 2" Author’s parenthesis.

51. See Boehner, "Ockham’s Theory of Truth," Collected Articles on Ockham, pp. 174-200; also pp. 253-267.

52. Ibid., III, c. 36. This rule can be symbolized in the following theorem: (p q ) )- ( p - q ).

53. See P. Boehner, "The Metaphysics of William Ockham," The Review of Metaphysics, I (1947-1948), 59-86. Reprinted in Collected Articles on Ockham, pp. 373-399. P. Lucey, Metaphysics and the Philosophy of William of Ockham (Rome: Pontificia Universitas Gregoriana, 1954).

54. Rep., III, q. 9, T.

55. Summa of All Logic, I, c. 38.

56. Rep., III, q. 9, T.

57. Ord., d. III, q. 8.

58. Ibid.

59. Quodl., I, q. 13.

60. Ord., I, d. 3, q. 2, Y.

61. Ibid. "These remarks suggest that the general terms of the category of substance are not as absolute as Ockham elsewhere supposed, and that the only nonconnotative concept is the transcendental concept `being.’" E. Moody, "William of Ockham," Encyclopedia of Philosophy. 8, p. 313.

62. Ibid., III, 2, c. 27.

63. Ibid.

64. Ibid.

65. Summa of all Logic, I, 11, c. 55.

66. Ord., d. II, q. 9, P.

67. Rep., III, q. 8.

68. Ibid.

69. Ibid.

70. Ord., d. I, q. 35, 5, N. Rep.. II, q. 3, 8.

71. Quodl., IV, q. 1. See H.A. Klocker, "Ockham and Efficient Causality," The Thomist, 23 (1960), 106-123. Also "Ockham and Finality," The Modern Schoolman, 43 (1965-1966). 233-247.

72. 0rd., I, d. 1, q. 3, N.

73. Rep., II, q. 5, R, S.

74. Rep., II, q. 4-5.

75. Ord., d. II, q. 9, P. See H. A. Klocker, "Ockham and the Cognoscibility of God," The Modern Schoolman, 33 (1957-1958), 77-90.

76. Ord., d. II, q. 9, P.

77. Ibid.. d. II, q. 9.

78. Rep., d. III, q. 8.

79. Ord.. d. 1. q. 3, 2. M.

80. On Ockham’s view of efficient causality, see H.A. Klocker, William of Ockham and the Proofs for the Existence of God (Roma: Università Gregoriana, 1955.

81. Quaestiones in lib. I Physicorum, q. 135.

82. Ibid., q. 136. See Ord., d. I, q. 2, 10. But Ockham immediately pointed out that the first cause could be a celestial sphere: "I say that we do stop at a first efficient cause and there is no regress to infinity. It is sufficient that a heavenly body be posited because we do experience concerning such that they are the causes of others." Quodl., II, q. 1. See E. Woods, "Ockham on Nature and God," The Thomist, 37 (Jan., 1973), 69-87.

83. Summa of All Logic, III, c. 2.

84. Ord., d. I, q. 2, 6, D.

85. Quodl., I, q. 1, n. 6.

86. Ibid., III, q. 1. See M. Tweedale, "Scotus and Ockham on the Infinity of the Most Eminent Being," Franciscan Studies, 23 (1963), 257-267.

87. Ord., Prol., q. 2, DD.

88. Quodl., III, q. 3, n. 1.

89. See Ibid., VI, q. 6.

90. Rep., II, q. 19 F.

91. Ord., d. I, q. 35, 2, D.

92. Ibid., d. I, q. 35, 5, C.

93. Ibid., I, q. 35, 5, E.

95. Ibid.

96. Ibid., d. I, q. 36. 1. P.

97. Ibid.. II, q. 5, E.

98. Ibid., d. 38, C.

99. Ibid.

100. Ibid. See Predestination, God’s Foreknowledge, and Future Contingents. Trans. with an introduction by M.M. Adams and N. Kretzmann (New York: Appleton-Century-Crofts, 1969). Also Boehner, Collected Articles on Ockham, pp. 420-441.

101. Ord., d. 38, q. unica.

102. Ibid.

103. Ibid., I, d. 2, q. 1, F.

104. Ibid., I, d. 45, q. 1, C.

105. Ibid., I, d. 2, q. 1, D and F; 2, 2, G.

106. Ibid., I, d. 2, q. 1, BB.

107. Prologue to the Expositio super viii libros Physicorum.

108. Ord., I, d. 41, q. 1, E.

109. Ibid., I, d. 41, q. 1.

110. Quodl., IV, q. 30.

111. Summulae, III, 12.

112. Rep., II, q. 9, C, D, E; 12, D. Tractatus de successivis, ed. Boehner, p. 111. See H. Shapiro, Motion, Time and Place According to William Ockham (St. Bonaventure, N.Y.: Franciscan Institute, 1957).

113. See Ord., d. I, q. 30, I, R. It must be added, however, that Ockham restricted the application of this concept of relation to creatures and, as a theologian, recognized real relations in the Trinity.

114. Ord., I, d. 30, q. 5.

115. Tractatus de successivis, ed. Boehner, p. 47.

116. Ibid., p. 46.

117. Rep., II, q. 26, N.

118. Quodl., II, q. 5.

119. Ord., I, d. 44, M.

120. Summulae Physicorum, I, 14.

121. Ibid., I, 8.

122. Ibid., I, 15.

123. Quodl., I, q. 10. Author’s parenthesis.

124. Ibid.

125. Ibid.

126. Rep., II, q. 22, H.

127. Quodl., I, q. 10.

128. Rep., II, q, 24.

129. Ibid., II, q. 26, D and E.

130. Ibid., II, q. 15, Q.

131. Ord., I, q. 27, 3.

132. Comm. on Perihermenias, I, Q-R.

133. Rep., II, q. 15, T.

134. Ibid., II, q. 24, Q.

135. Comm. on Perihermenias, II, 25, A, O; II, 15, XX. 136. Rep., II, q. 24, P.

137. Ibid., II, q. 25, K.

138. Quodl., I, q. 16.

139. Ibid., "Liberty is a certain indifference and contingency, and is distinguished from a natural active principle." Ord., I, d, 1, q. 6.

140. Rep., IV, q. 14, G.

141. Expositio super Physicam Aristotelis, fol. 117a. 142. See Rep., III, q. 13, U.

143. Quodl., III, q, 13.

144. Like Peter Abelard before him and Kant after him, Ockham was concerned with distinguishing morality from legality.

145. Ord.. d. 1. q. 6.

146. Quodl., VII, q. 20.

147. Ord., d. I. q. 1, 4, E.

148. Ibid., d. I, 6, P.

149. Rep., III, q. 1, 8.

150. Quodl., IV. q. 11.

151. Ord., I, d. 23. q. 1, C.

152. Quodl., II, q. 14.

153. Rep., II, ProI.. q. 1, BB.

154. Ibid., II, d. 9, F.

155. Ibid., II, q. 4-5. H; 19, P; IV, 8-9, E.

156. Ibid., II, q. 5, H.

157. Ibid., II, d. 19, q, 1, F.

158. Ibid., II, q. 19, P. See IV, 9, E-F.

159. Ibid., IV, d. 14, D.

160. Quodl., III, q. 13.

161. Rep., II, q. 19, N, 0.

162. Ord., I, d. 41, K.

163. Rep., III, q. 12, C-D.

164. Ibid., III, q. 12, T.

165. Ibid., III, q, 13, O.

166. See Opus nonaginta dierum, c. 95. See F. Oakley, "Medieval Theories of Natural Law: William of Ockham and the Significance of the Voluntarist Tradition," Natural Law Forum, 6 (1961), 65-83.

167. See Boehner, "Ockham’s Political Ideas," Collected Articles on Ockham, pp. 442-468.

168. Breviloquium, lib. III, c. 7. Private ownership is "the power of appropriating some temporal thing for one person or some special group . . ." Ibid.

169. Brevil., lib. III, c. 7.

170. Ibid., c. 6.

171. Dialogus, 22, 6.

172. Brevil., lib. III, c. 2.

173. Dialogus, 1, 3, 24.

174. On the Power of the Emperor and the Pope, 1. 3.

175. Brevil., lib. II, c. 3.

176. An princeps, c. 4.

177. Octo Quaestiones, q. 3, c. 8.

178. On the Power of the Emperor and the Pope, II, 3.

179. Octo Quaestiones, q. 2, c. 8.

180. Ockham distinguished between regular power which excludes interference and casual power by which the Pope may help in the deposition of a king guilty of a crime, and the Emperor can punish a pope who has committed grave crimes against public security. See Boehner, Collected Articles on Ockham, pp. 465-468.

181. An princeps, c. 4. Brevil., lib. II, c. 5.

182. Brevil., lib. III, c. 7.

183. Ibid., c. 15.

184. Dialogus, 2, 3, 1, 27; 2, 3, 2, 6. Opus nonaginta dierum, 2, 4.

185. Brevil., lib. IV, c. 14.

186. For that reason, Boehner prefers to call Ockham a "conceptualist." See "The Realistic Conceptualism of William Ockham, op. cit., pp. 156-174.

187. E. Moody, "William of Ockham," The Encyclopedia of Philosophy, 8, p. 307. See R.G. Turnbull, "Ockham’s Nominalistic Logic: Some Twentieth Century Reflections," New Scholasticism, 36 (1962), 313-329.

188. See D.W. Clark, "Voluntarism and Rationalism in the Ethics of Ockham," Franciscan Studies, 31 (1971), 72-87. Different interpretations of Ockham seem to arise from an emphasis on one of these three characteristics: Nominalism gives rise to E. Gilson’s judging him a skeptic, empiricism to E. Moody’s insistence on his Aristotelianism, and voluntarism to P. Boehner’s recognition of his carrying on Franciscan tradition. See Gilson, Unity of Philosophical Experience (New York: Scribner’s, 1937), pp. 61-91. Moody, The Logic of William of Ockham (New York: Russell and Russell, 1965), Ch. I. Boehner, "The Spirit of Franciscan Philosophy," Franciscan Studies, N.S. II (1942), p. 220.

189. D. Knowles, The Evolution of Medieval Thought (Baltimore: Helicon Press, 1962), p. 321.

190. "According to them (De Morgan laws), the contradictory opposite of a conjunctive proposition is equivalent to a disjunctive proposition in which each proposition is denied." For example, the contradictory opposite of the propositions "Socrates is white and Plato is black" is "Socrates not white or Plato is not black." In terms of symbolic logic, Ockham knew the law: -(p . q) .-(.pv-q). Boehner, "Introduction," Ockham, p. xxxvii; also pp. 80-81.

191. See Boehner, Collected Articles on Ockham, pp. 156-174.

192. See A.M. McCords, "Intuitive Cognition, Certainty, and Skepticism in William Ockham," Traditio, 26 (1970), 388-398. Also R.C. Richards, "Ockham and Skepticism," New Scholasticism, 42 (1968), 345-363.

193. E. Moody, "William of Ockham," Encyclopedia of Philosophy, p. 313.

194. See H.A. Klocker, "Empiricism and Reality: Ockham and Hume," The Heythrop Journal, 4 (1963), 42-53.

195. Le Tractatus de Principus Theologiae attribués a Guillaume d’Occam, ed. L. Baudry (Paris: J. Vrin, 1936).

196. For Luther’s relation to Ockham, see P. Vignaux, Luther, Commentateur des Sentences (Paris: J. Vrin, 1935).






Heynck. V. "Ockham Literatur 1919-1949," Franziskanische Studien, 32 (1950), 164-183.

Reilly, J.P. "Ockham Bibliography: 1950-1967," Franciscan Studies, 28 (1968), 197-214.




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Boehner, P. ed. and trans. Ockham, Philosophical Writings. Edinburgh: Nelson, 1957. (English translation only in paperback edition by Bobbs-Merrill, "The Library of Liberal Arts," Indianapolis, 1964.)

McKeon, R. ed. and trans. Quodlibets, Selections from Medieval Philosophers II, Roger Bacon to William of Ockham. New York: Scribner, 1958. Tornay, S. ed. and trans. Ockham, Studies and Selections. La Salle, Il.: Open Court, 1938.




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Bergmann, G. "Some Remarks on the Ontology of Ockham," Philosophical Review, 63 (1954), 560-571.

Bird, O. "Topic and Consequence in Ockham’s Logic," Notre Dame Journal of Formal Logic, 2 (1961), 65-78.

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Day, S. Intuitive Cognition: A Key to the Significance of the Later Scholastics. St. Bonaventure, N.Y.; Franciscan Institute, 1947.

Ghisalberti, A. Quglielmo di Ockham. Milano: Publicazioni della Università Cattolica del Sacro Oure, 1972. Contains bibliography of Ockham from 1950-1970.

Guelluy, R. Philosophie et théologie chez Guillaume d’Ockham. Louvain: E. Nauwelaerts, 1947.

Menges, M.C. The Concept of the Univocity of Being Regarding the Predication of God and Creature According to William Ockham. St. Bonaventure, N.Y.: Franciscan Institute, 1958.

Moody, E. The Logic of William of Ockham. New York: Sheed & Ward, 1935.

. "Ockham, Buridan, and Nicholas of Autrecourt," Franciscan Studies, 7 (1947), 113-146.

. Truth and Consequence in Mediaeval Logic. Amsterdam; North-Holland Publishing Company, 1953.

. "Empiricism and Metaphysics in Medieval Philosophy," Philosophical Review, 67 (1958), 145-163.

Pegis, A. "Some Recent Interpretations of Ockham," Speculum. 23 (1948), 458-463.

. "Concerning William of Ockham," Traditio, 2 (1944), 465-480.

Shapiro, H. Motion, Time and Place According to William Ockham. St. Bonaventure, N.Y.: Franciscan Institute, 1957.

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