John of Salisbury (d. 1180) estimated that more time was taken up discussing the problem of universals than the Caesars required to conquer and govern the world. In fact, the problem runs like Ariadne’s thread through eleven centuries, from Porphyry in the third century to William of Ockham in the fourteenth century, spanning a longer time than the life of the ancient Roman Empire. This chapter centers on the emergence of the problem with Boethius (c. 480-524/525) — prime minister to Theodoric, the Ostrogoth King of Italy — and its solution by Peter Abelard (1079-1142).

I. Emergence of the Question

II. Ontological Question

On the one hand, a universal, such as the species "man," which at one and the same time is common to many individual men, cannot be a reality, for everything in reality is singular and one in number. To the objection that the universal is common to many by parts, as though each possessed only a part of the species, Boethius affirmed that each individual possesses the species entirely inasmuch as each man is wholly man, and each species has the genus completely insofar as each species of animal is totally animal.

To the objection that the universal is successively common to many as a horse is used by many at different times, Boethius insisted that species and genus constitute the very substance of the things to which they are common. Since a universal is substantially common to many, how can it be one in reality?

On the other hand, it seems equally impossible for universals to be simply mental concepts. If universal concepts do not correspond to a universal reality which, as we have seen, does not actually exist, they do not represent reality as it is, and consequently they are false. In view of these ambiguities, universals seem to be neither realities nor concepts. What is their status?

III. Psychology and Epistemology

This ontological question confronting medieval dialecticians such as Peter Abelard was connected with the psychological question of how universal concepts are formed by the mind. If the senses experience only individual things, as Aristotle insisted, how can the mind produce universal concepts? Within this ontological and psychological context, there arises the epistemological question of how universal concepts are related to reality. How can universal concepts validly represent individual things from which they differ? Without a foundation in extramental reality, universal concepts and judgments would be of doubtful validity at the very least.

IV. Theology

If universals were not connected with individual reality in some way, scientific knowledge of God as well as of the world and man would lose its objective value. For example, the universal concept "wisdom" would not refer to something in God. No wonder Christian philosophers were deeply concerned about the outcome of the problem of universals. In addition, Augustine interpreted Plato’s ideas as a philosophical statement of the Christian conviction that God has universal and eternal knowledge of all that can come to be. Of what value is divine knowledge if universals have no reference to reality?

In their investigation of tho problem of universals, medieval dialecticians agreed in recognizing the fact of universals, such as the genus "animality" and the species "humanity," but disagreed on the meaning of the fact, which they expressed in different themes. Universals were viewed by ultra-realists as subsistent realities, by nominalists as names, and by some realists, such as Abelard, as names and concepts with a foundation in reality.

In their approach to the problem of universals, the dialecticians adapted their method to their basic theme. On the one hand, ultra-realists tended to adopt a Neoplatonic method paralleling the ontological and logical orders in which universals in reality exactly correspond to general concepts in the mind. On the other hand, Roscelin, the nominalist, differentiated these orders to such an extent that he understood universals simply as words within a logical or more exactly, grammatical context. In his realistic approach embracing both the logical and ontological orders, Peter Abelard attempted to steer a middle course between ultra-realism and nominalism with the intention of grounding universal concepts and names in individual realities.

The ancient Greek philosophers set the stage for the problem of universals and determined the direction taken by various solutions. In attempting to reconcile the teachings of Plato and Aristotle, Porphyry, as we have seen, first posed the problem in terms of genus and species. To determine the status of universals such as genera and species, the medieval philosophers relied on either the Platonic tradition of positing universal ideas beyond individual sensible things or the Aristotelian heritage of locating forms in individual realities.

Both the problem presented by Porphyry and a solution with Platonic and Aristotelian elements were transmitted through Boethius to medieval logicians. The influence of Plato predominated in Boethius and earlier medieval dialecticians who reified universal genera and species, whereas the realism of Aristotle via Boethius gradually gained ascendancy in the eleventh and twelfth century dialecticians: Abelard, Gilbert of Poitiers, and John of Salisbury.

I. Boethius

How is it possible for incorporeal genera and species to exist in sensible bodies and yet be understood apart from them? When the observed substantial likeness of several individuals is conceived by the intellect, it becomes a species. For example, the mind conceives the species "man" from the human likeness of individual men. The concept gathered from the likeness of different species is a genus. Sensible in individual things, the likeness conceived by the intellect is intelligible. Universals, consequently, enjoy two modes: in reality they exist in sensible bodies, whereas in the mind they are thought apart from these bodies.

This solution to the problem of universals in Alexander of Aphrodisia’ interpretation of Aristotle differs, according to Boethius, from Plato’s teaching that genera and species are not only known separately from bodies but also exist outside them. In his commentary on Porphyry’s Isagoge. Boethius reserved his judgment on the correctness of these views to a loftier branch of philosophy than logic.

When the problem of universals was taken up again about four centuries later, the first solution was not along the broad lines suggested by Boethius, but was ultra-realistic.

II. Ultra-Realists

From the ninth to the twelfth century, ultra-realists preferred Boethius’ Platonic approach. According to this view, generic and specific concepts correspond to an extramental, existing reality in which individuals share. For example, the concept "humanity" reflects a unitary substance which exists in the same way as it is thought and in which all men participate.

On the supposition that thought and reality exactly parallel each other, it is logical to posit as much universality in reality as in the mind, and to reason, for example, that because the meaning of "man" in the statements "Plato is a man" and "Aristotle is a man" is the same, there is a substantial identity in the real order between Plato and Aristotle. The advantage of this theory is that it securely grounds the scientific knowledge of philosophy and theology in the objective reality of universals.

If this view means that the plurality of individual men have a common substance which is numerically one, then all men differ only accidentally. This is the conclusion of Odo of Tournai (d. 1113) who held that at the birth of a child God produces, not a new substance, but simply a new property of an already existing substance which is one specific reality for all men. Consequently God is not responsible for original sin in a child, rather the human substance of Adam infected by original sin, is handed on at generation. Theological as well as logical reasons motivated philosophers to adopt an ultra-realist theory.

III. Opponents of Ultra-Realists

The adversaries of the ultra-realists affirmed as their guiding principle the Aristotelian axiom that only individuals exist. For Eric of Auxerre (841-876) general names, such as "white" or "black," have no general or universal realities corresponding to them; their only objects are individuals, as this white man or that black horse. Species does not exist as such, but is merely a way in which the mind groups individuals, and genera are simply the gathering together of species under one name. Eric’s rejection of ultra-realism and his psycho-logical explanation of universal concepts do not involve sufficient evidence to conclude that he denied any basis in reality to universal concepts.

IV. Nominalism

V. Moderate Realists

The dispute between the ultra-realists and their opponents came to a head in the controversy between William of Champeaux and Peter Abelard.

A. William of Champeaux (c. 1070-1121): Theory of Identity. William represented a transition from an ultra-realist theory of identity to a kind of moderate realist theory of indifference. Though a student of Roscelin, William at first returned to the realism of Boethius and taught that universals are substances common to many individuals. Because the same essential nature is wholly present at the same time in each individual member of a certain species, individuals of that species differ only accidentally from one another. For example, Plato and Socrates share the same substance of humanity and individually differ by reason of their accidental characteristics, such as personal qualities, quantities, places, and so on.

If this were so, William’s pupil, Abelard, objected that humanity would be either partially or wholly in an individual. If it is only partially present, this individual is not truly and wholly man. If it is wholly present, no other individual man can exist. Furthermore if all things are identical in substance, they are the same as God who himself is substance. Lastly, if the substance animal really exists in man and beasts, the same animality would itself be in the situation of being rational and irrational — an impossible contradictory condition. Abelard’s dialectical disclosure of the absurd consequences of ultra-realism sealed its downfall.

Abelard, however, went beyond Roscelin’s view of universals as vocal utterances and conceived them as words with meaning. The sentence, "man is a stone," is grammatically correct but wrong from the viewpoint of the meaning of the words. Universals are not simply words (voces) in the sense of a physical entity which cannot be predicated of another thing, but are words (sermones) which function as signs with a logical content which is predicable of another.

Common names correspond to universal concepts which signify in a confused and indistinct manner the same individuals represented in a detailed way by particular concepts. Universal concepts are formed by abstraction or the attention of the mind upon one aspect of a thing to the disregard of other features of the same thing, for example, thinking of man as substance apart from the other forms that exist together in him.

Abelard summarized his doctrine of universals by replying like Boethius to the questions raised by Porphyry.

Gilbert of Poitiers and John of Salisbury, two notable figures connected with the School of Chartres, broke with its old tradition of ultra-realism.

Abelard, the outstanding dialectician, and for that matter, the eminent philosopher of the twelfth century, went beyond ancient philosophy in probing and resolving the problem of universals and contributed to ethics and the development of the scholastic method. In retrospect, the numerous solutions combating ultra-realism can be viewed as so many steps toward Abelard’s realism mediating between nominalism and exaggerated realism.

The naive view of the ultra-realists misunderstands Boethius’ exposition of the problem by assuming that unless the thing expressed by the concept exists in reality in exactly the same way that it exists in the mind, the concept is purely subjective. The ultra-realist naively assumes that the only way of saving the objectivity of knowledge is to have a one to one correspondence between concept and reality.

What is significant about Abelard’s response to the problem of universals is his going beyond logical and verbal analyses to coordinate the metaphysical status of universals with their psychological formation and their epistemological value to constitute a solid, coherent theory. This does not mean his theory was without difficulties. For instance, the objectivity of universal names and concepts seems to be open to question if they are grounded in the common likenesses of individuals with no intrinsic essences or natures in common.

Gilbert of Poitiers’ psychological theory of abstraction and comparison identifies him as a moderate realist. His unique distinction between common and individual form or essence caused difficulties in theology. Applying that distinction to the doctrine of the Trinity, he differentiated between God (Deus) and Godhood (Divinitas), Father (Pater) and Fatherhood (Paternitas), as he would between Socrates and humanity. After being accused of impairing the unity of God, he retracted his unacceptable theological propositions.

Hugh of St. Victor (1096-1141) adopted more or less the position of Abelard and applied the theory of abstraction to mathematics and physics. The mathematician, for example, abstracts or isolates geometric elements as the line or the plane surface without their existing apart from bodies. Likewise, the dialectician considers the forms of things in abstraction as a unified concept, though in reality the forms of sensible things exist neither in isolation from matter nor as universals.

Not infrequently, the position taken by the dialecticians made itself felt in theological issues. For example, Odo of Tournai’s view of one substance in all men facilitated his explanation of original sin which is handed on at generation from Adam to other individuals without making God responsible for the sinfulness of every particular human substance. Roscelin’s nominalism led him to propose a form of "tritheism" which was criticized by Anselm of Canterbury and censured at the Council of Soissons. For Anselm, such conflicts between dialectics and faith need not arise.

John of Salisbury criticized his contemporaries for trying to solve philosophical problems by logic which is barren by itself. While it is an aid to the other disciplines, dialectic needs to be impregnated by the real sciences.

John’s attitude found favor with the thirteenth and fourteenth century masters who probed deeply into the metaphysical and psychological significance of the truth about universals. In the thirteenth century, Thomas Aquinas developed Abelard’s moderate realism in view of Aristotle’s metaphysics and psychology to clarify the objective foundation of universal concepts and how they are formed by the mind. In the fourteenth century, William of Ockham took up afresh the problem of universals and resolved it in a nominalistic way that revolutionized philosophy.

In their concern for the epistemological value of knowledge, modern philosophers will investigate the problem of universals in ways unknown to medieval thinkers or, at least, not employed by them. Nevertheless, the nominalist, conceptualist, and realist positions of the medievalists find ardent defenders from the seventeenth to the twentieth centuries.

2. Boethius, The Second Edition of the Commentaries on the Isagoge of Porphyry, bk. I, 10; R. McKeon, trans., Selections from Medieval Philosophers, I (New York: Charles Scribner’s Sons, 1957), p. 91. Reprinted by permission.

3. Ibid., I, 11.

4. Consolation of Philosophy (New York: Modern Library, 1943).

5. De Hebdomadibus; see Boethius: The Theological Tractates, ed. E.K. Rand (Cambridge, Mass.: Loeb Classical Library, 1962), pp. 38.50.

6. Boethius, De Trinitate, 2.

7. Commentaries on the Isagoge of Porphyry, I, 11.

8. Ibid.

9. See Chapter III below.

10. Knowledge of Roscelin’s thought is derived almost entirely from his adversaries, St. Anselm and Abelard. See St. Anselm, De Fide Trinitatis, 2, Opera Omnia, Patrologia Latina, t. 158, c. 256A. Abelard, Liber divisionum, Oeuvres inedites d’Abelard (Paris: Imprimerie Royale, 1836), p. 471.

11. See F. Picavet, Roscelin philosophe et theologien (Paris: F. Alcan, 1911), pp. 112-143.

12. See "Guillemi Campellensis Sententiae vel Quaestiones XLVII," in G. Lefèvre, Les variatione de Guillaume de Champeaux et la question des universaux (Lille: l’Univers. de Lille, 1898. Also Eugene Michaud, ed., Guillaume de Champeaux et les écoles de Paris au XIIe siècle, d’après des documents inédits (Paris: Didier, 1867).

13. Abelard, Glosses on Porphyry. trans. R. McKeon, Selections from Medieval Philosophers, I (New York: Charles Scribner’s Sons, 1929), pp. 222-232.

14. Ibid., op. cit., p. 232.

15. Abelard, "Glosses on Porphyry," trans. A. Wolter, Medieval Philosophy (New York: The Free Press, 1969), p. 194. Reprinted by permission.

16. Ibid., p. 200.

17. Ibid., p. 201.

18. Ibid., p. 202.

19. Ibid., pp. 250-254.

20. John of Salisbury, The Metalogicon, trans. D. McGarry (Berkeley: University of California Press, 1955), II, 17, p. 115.

21. Gilbert, In Boethii Librum de Duabus Naturis, Patrologia Latina 64, 1372 D.

22. Ibid., 64, 1267 and 1389.

23. John of Salisbury, The Metalogicon, II, 20; III, 3.

24. For example, Boethius’ definition of person as "an individual substance of a rational nature," "Contra Eutychen et Nestorium", in Scripta veterum latina, J. Simmler, ed. became classical among medieval philosophers.

25. That is why a nominalist or conceptualist interpretation of Abelard seems unwarranted.

ABELARD

BOETHIUS

JOHN OF SALISBURY