Nominalism Notes

In the sentence 'Peter is a rabbit.', 'is a rabbit' is the predicate. In this case, the subject may refer to a rabbit Peter (supposing that there really is one), but the predicate can not refer to a rabbit. Call the collection of all things that a predicate applies to the extension of that predicate. In the case of 'rabbit', the extension is the collection of all rabbits. The question we ask is what is it that puts rabbits in the extension of 'rabbit'? Put another way, the question is, what do rabbits have in common?

Answer I: Realism

Rabbits have in common there membership in either of the biological families Leporidae or Lagomorpha, of the order Rodentia, and of the class Mammalia. These categories (not just the members of the categories, but the categories themselves) exist in nature; they are natural kinds. Realists offer an account of the history of the term 'rabbit' and other predicates that goes like this: As a result of interacting with rabbits and with other animals, humans have discovered the rabbit category (at least approximately) and developed the predicate term 'rabbit' to designate it. Rabbithood, the property of being a rabbit, is often called a universal, meaning a characteristic that many things share. Realist say that there really are universals, but may disagree on their status. In the debate in medieval philosophy, realists like Plato who maintain that universals can exist even if there is nothing they apply to are advocating universalia ante rem, universals prior to the things that may have them. Realists like Aristotle who maintain that universals only exist in the things that have them advocated universalia in rem, universals in the things that have them.

Realists don't have to maintain that every predicate denotes a natural kind, or even that the things that fall under it really have something in common. One might deny this for 'totalitarian', for example, which was a term invented to assert that fascism and communism are fundamentally the same. Nietzsche's example is 'honesty'.

Answer II: Nominalism

Nominalist maintain that the only thing that all that rabbits have in common is the word 'rabbit', and the various criteria and marks for the correct use of that word in English. There is no such thing as rabbithood, and 'rabbit' does not correspond to any natural kind. The collection of marks or criteria of correct usage of a predicate term is called nominal essence by Locke. Nominalists say that the only kind of essence that a predicate can have is a nominal essence.

In recent analytic philosophy nominalism is the view that predicates not only don't correspond to universals, but there are no extensions of predicates, either. An extension is a collection, so an abstract object, so can't exist, says this kind of nominalist, since there are no abstract objects. Example: Nelson Goodman.

Answer III: Conceptualism

The rabbithood that the realists talk about Locke called the real essence. He though that such a thing must exist, but we don't know anything about what it is. What the word 'rabbit' actually refers to, Locke thought, is a general idea of rabbithood that the mind produces from the ideas of particular rabbits by various psychological operations. The idea that universals are mental is called conceptualism. Thus Locke was a conceptualist. Perhaps this view should be regarded as a mere variant of nominalism.

Problem for Nominalism:

(*) "If there had been no humans, there would have been no rabbits."

The nominalist maintains that what makes a rabbit a rabbit is the use of the word 'rabbit', and its associated linguistic criteria. The word and the criteria would not have existed if there had been no humans, since the word and criteria are part of human language. Thus there would have been no rabbits if there had been no humans. Note that a nominalist might say that the things we call rabbits might have existed without humans, but they could not be rabbits without humans, since there is nothing outside human language that 'rabbit' refers to. Several of Nietzsche's comments in the Truth and Lie suggest that may well have realized that he is committed to this view. Note the difference between (*) and the following statement, which I think most people would agree is true:

(**) "If there had been no humans there would have been no Dachshunds"

My reason for saying this is true is my guess that such a ridiculous animal is unlikely to have evolved on its own, without human intervention. This is not to say that there is not universal Dachshundhood.

Specific Problems with Nietzsche's nominalism:

Nominalists, and apparently Nietzsche, want their nominalism to extend to social categories just as much as natural ones. For the things that humans have invented, the question of whether or not they fit into the same category is not a question of how they are intrinsically, but only of how they are classified by some (essentially arbitrary) linguistic conventions. That is, if you are going to be a nominalist about the existence of forms or kinds in nature, why not say the same about social institutions, like language. But that gives the following problem: Nietzsche would like to assert that the same word ('red') is applied to things x and y that are not (really, objectively, or in essence) the same or even similar. But if there is no real or objective similarity of distinct squiggles which are conventionally classified as inscriptions of the word 'red', then how can one say that the same word is actually applied to different individual things, as opposed to saying that not the same word but merely words conventionally classified as the same are applied to different things? This latter claim may be quite compatible with the conclusion that the same word is not actually applied to distinct things. Moral of the story: you need some objective sameness (or difference) to assert the non-objectivity of claims of sameness and difference.

Problems about denying truth:

The problem that we just mentioned, that you need to assume some objective sameness to deny objective sameness, has a exact analogue with truth. Nietzsche is offering the claim "all truth are illusions" as a truth (even the deflationary view would be enough to get this conclusion). He is therefore committed to say that his own position is an illusion! You get a similar result if you want to make a more restricted statement that doesn't reject all truths, but only the philosophical ones. The statement "there are no philosophical truths" (meaning there are no truths on philosophical subjects) is easy to disprove. Suppose it were true that there are no philosophical truths. Then "There are no philosophical truths" would be a true statement on a philosophical subject, which contradicts our supposition that there were no philosophical truths.

This kind of argument pattern (called reductio ad adsurdum, or reduction to absurdity) says that if the supposition that a statement is true leads to a contradictory result, then the statement is false, and its negation is true. Since this argument pattern is a firmly established part of logic, asserting that there are no philosophical truths means giving up logic. Nietzsche sometimes heaped abuse on logic, but he does make use of this same argument pattern himself. In Beyond Good and Evil, §15, he gives the following perfectly sound refutation of (one version of) phenomenalism, the view that physical objects are collections of sensations:

"What's that? And other people are actually saying that the external world is created by our sense organs? But then our body, as part of this external world, would be--the creation of our sense organs! It seems to me that this is a complete reductio ad adsurdum: assuming the concept causa sui [cause of itself] is something completely absurd. If follows that the outer world is not the creations of our sense organs-?"

Comment on the question in class on Abelard:

According to Abelard's theory, universals existed first in God's mind, then in things as similarity of the essential marks of individual things that fall under the universal, and finally in human understanding through comparative thought and acquired concepts. Paraphrased from Windelband: Lehrbuch der Geschichte der Philosophie, page 249