Medieval Philosophy Peter Abelard William of Ockham on Universals

Peter Abelard and William of Ockham on Universals

William of Ockham is a notable adherent of nominalism -- the notion that universals, the supposed referents of general terms, have no real existence. His objection to the notion of realism as applied to the concept of universals can be summed up in his phrase 'no universal is a particular, since every universal is capable of signifying many and of being predicated of many'. The soul alone is a universal by nature; universals as they have otherwise been understood, which is to say general terms such as those of colour, size, material, composition, are for Ockham matters of language and convention, not of reference to actually existing universal properties:

Thus a spoken word, which is numerically one quality, is a universal; it is a sign conventionally appointed for the signification of many things. Thus, since the word is said to be common, it can be called a universal. But notice that it is not by nature, but only by convention, that this label applies.

Peter Abelard is also a nominalist, in that he rejects the concept of actually existent universal qualities of which objects in the world partake their particular qualities. Yet Abelard is in important respects less concerned with things than with words. He accepts that there are universal words; the question is whether there are universal things corresponding to those words. William of Ockham's view is clear enough: there are not. What does Peter Abelard say? The first thing he does is to turn to Aristotle's definition of a universal as 'that which is of such a nature as to be predicated of many' as opposed to the individual which 'is not something of that kind'; but when Aristotle goes on to suggest that 'The genus specifies the quality with reference to substance, for it signifies what sort of thing it is' so that 'things as well as words are called universals', Abelard opposes his view. He argues that to take the characteristics of a thing as indicating its possession of universal qualities is first to mistake the essence of things for their accidental qualities, and second to engage in circular reasoning, using the fact that certain qualities appear to reflect universals to reach conclusions about the nature of the universals they appear to reflect. Furthermore 'things taken either singly or collectively cannot be called universals, because they are not predicable of many', so an individual human being cannot be taken as the universal human being because this leads to the conclusion either that the individual is common to many or that there are as many universals as there are individuals, rendering absurd in both cases the very concept of the universal. If, then, the universal cannot be located in things it must exist only in language:

Consequently it remains to ascribe this form of universality to words alone ... A universal word is one which is able to be predicated of many by reason of its intention, such as the noun 'man', which can be joined with the names of particular men by reason of the nature of the subject on which they are imposed.

Clearly, unless a number of things are in the same state, a universal term cannot be applied to them. Abelard's position is thus that although universals are not themselves real things, it is the existence of a common feature in real things that allows the predication of a universal of them. There is no independently existing 'real' color red, but when we recognize similar conditions of color in otherwise different objects amounting to the presence of what we recognize as red, we are justified in applying the term 'red' to them. The applicability of the term comes from the things' relationship to each other, not their supposed relationship to some really existing external quality of redness other than the one that is present in the term 'red'.

Would William of Ockham agree with this position? Fundamentally, the answer is yes. He is quite clear that universals are not substances but exist only in the mind's response to the qualities of the things it perceives:

... It is clear that the universal is an intention of the soul capable of being predicated of many. The claim can be corroborated by argument. For everyone agrees that a universal is something predicable of many, but only an intention of the soul or a conventional sign is predicated. No substance is ever predicated of anything. Therefore, only an intentional of the soul or a conventional sign is universal; but I am not here using the term 'universal' for conventional signs, but only for signs that are universals by nature.

It is difficult to see how this position is any more strongly nominalist than Peter Abelard's. Both Abelard and Ockham argue that universals cannot represent substances, for no substance can simultaneously compose individual things and a universal thing; that the recognition of common qualities occurs in the mind and that an intention of the mind to predicate those qualities finds expression through the use of universal terms; and that universals can only be said to exist in those terms.

If Abelard's position could be understood as moderate realism one would expect to find him arguing that the properties upon which the predication of universals depends have an existence independently of human perception and language. Thus the sentence 'the grass is green' can only be meaningful if the grass possesses the quality of greenness existing independently of what we may think and say about it -- just as grass itself does. Abelard does not argue this; he argues the contrary. In answer to the question 'whether the ability of universal words to refer to things in general is due to the fact that there is in them a common cause for imposing the words on them, or whether it is due to the fact that a common concept of them exists' he comes down clearly on the answer involving common cause, not common concept. However, he does then complicate matters by considering the status of sensory knowledge -- something that William of Ockham does not address. For Ockham the purely linguistic nature of universals is established and beyond argument and the relationship of such linguistic terms to the means of gaining the understanding upon which they are based is not a relevant consideration. For Abelard, however, it is, and he considers at some length the distinction between 'sensible' and 'non-sensible' qualities, and the consequences of that distinction for the notions of particular and universal.