Nominalism

The “problem of universals” is something of a philosophical chestnut that has bedeviled philosophers at least from the time of Plato onward. Generally, there are two camps: realists and non-realists. Nominalism is one of several “non-realist” attempts to account for “universals.” The Nominalist denies that there are such things as “Universals” (as opposed to the metaphysical/epistemological position to “Realism” w/r/t Universal).

When we look at to instances of a kind and so label it, there is a tacit implication that there exists a third thing, namely, that which all and only instances of the kind share and by virtue of which they are instances of that kind. (Recall Plato who asks “What is it that all just acts have in common by virtue of which they are just acts? Answer: The Form of Justice.[1]) According to the Realist, the best explanation of the fact that two white pieces of paper are white (or whatever) is that there is a single universal (e.g. “Whiteness”- “Form of White”) that is in each piece of paper, or that each of the two pieces of paper exemplifies (or that each “participates in” to use Plato’s phrase). This commits the Realist to the claim that “there is something” over and above the particular objects which explains why/ how they share certain properties. But this quantification becomes “mysterious;” what might this “something be?

The Nominalist, on the other hand, claims that when we say both pieces of paper are white we are only asserting that both are members of a certain class, specifically, the class we name “all-and-only-the-white-things.”

Now this might seem too circular to be an explanation of why two things are both white. One seems to be saying that two things are white if and only if they both belong to the class of “White Things.” But the Nominalist is claiming that the only thing that binds the class of white objects together is that we happen (to choose) to so classify them. The “fact” that both are white is not a fact about reality to be explained by appealing to Universals, but a linguistic fact about our naming habits. We have NOT latched onto some metaphysically real shared property, but, for whatever reason, have chosen to group a certain set of particular items together. And while the set is “real” it does not commit us to the existence of anything beyond its own particular members.

One might object that not all sets a thing might belong to are relevant to determining what kind of thing it is. In other words, while we might group a dog, an ashtray and my wedding ring together under the class, “Things that I lost on a Tuesday,” nevertheless we would say that the dog’s “dogness” is an essential quality of the dog and its membership in the class of “Things I lost on a Tuesday” as an accidental property. But from a nominalist perspective, since all classes are equally real, neither categorization is metaphysically privileged, merely more or less useful to us depending on what we’re trying to get done. All sortings are ultimately arbitrary and equally “real.” No matter what individuals you pick, no matter how dissimilar they are, there is a class containing all and only those things.[2]

Still, it would appear that some classes to which the thing belongs are more salient, more central to the thing’s identity. After all, we seemed to discover that water is H20, not merely to conventionally define it so. Further, “dogs” seem to sort themselves and our linguistic sorting behavior, realists would argue, is an attempt to mirror the natural kinds evidenced in our experience of the world. What the Nominalist lacks (in fact seems to deny) is any way of specifying certain classes as “natural kinds.” Since all sets are equally real, the Nominalist denies that any sets, even sets such as “dog” “water” or “gold” have ontological priority or are inherently more significant that other sets we might construct. At best, they are like designations such as “Hispanic American;” that is, they be sets we have found to be useful or expedient for one purpose or another, but according to the nominalist, we must resist the temptation to think that we referring to any inalterable objective fact or are “cutting reality at the joints[3]” to use Plato’s phrase.

Now of course, one need not be a realist about all common nouns to be a realist about some common nouns. For instance, it seems to me a nominalist account of “race” is entirely correct. What is it that all in only Hispanic Americans have in common by virtue of which they are Hispanic American? Well.. nothing I don't suppose. Yet we do craft this category through our social linguistic practices. The same might be said for “sandwiches.” Likewise, “birthday parties” names a real set of particular things, but they name all and only particulars we gather together through our social linguistic practices. And notice, birthday parties did not precede our social linguistic practices and will not persist if we cease to so construct them. By contrast, the realist would argue that this is not the case with such things as cats, dogs, gold, water, etc. They would argue that something like a realist account of universals is necessary for certain theoretical entities, such as the smallpox virus, to be used as an explanation for events which occurred before our social linguistic practices evolved to “create the category” smallpox virus.

Two Arguments for Fact Constructivism: Goodman and Putnam

Goodman's Reductio Pg. 32-3

1) Suppose a constellation exists, that there is a fact that there is a constellation made of those stars, so long as the stars that compose it exist

2) Then, any group of stars would be a constellation.

But (2) is absurd. (i.e. The only constellations that “exist” are the ones we confabulate.)

Therefore, (1) is false.

Therefore

(a) A constellation only exists if we classify it as one by distinguishing it according to some principle, and

(b) What principle we use is not constrained by the way the world “is,” but rather by our practical purposes.

Generalization: If constellations only exist because we classify them as such, then the same goes for food, fuel, giraffes, people, and everything else.

Therefore, no kind of object, or fact about objects exists, unless we come up with a term to designate that kind of object.

---

[1] Bertrand Russell in The Problems of Philosophy explains this as follows. "The way the problem arose for Plato was more or less as follows. Let us consider, say, such a notion as justice. If we ask ourselves what justice is, it is natural to proceed by considering this, that, and the other just act, with a view to discovering what they have in common. They must all, in some sense, partake of a common nature, which will be found in whatever is just and in nothing else. This common nature, in virtue of which they are all just, will be justice itself, the pure essence the admixture of which with facts of ordinary life produces the multiplicity of just acts. Similarly with any other word which may be applicable to common facts, such as "whiteness" for example. The word will be applicable to a number of particular things because they all participate in a common nature or essence. This pure essence is what Plato calls an 'idea' or 'form'. (It must not be supposed that 'ideas', in his sense, exist in minds, though they may be apprehended by minds.) The 'idea' justice is not 'identical' with anything that is just: it is something other than particular things, which particular things partake of. Not being particular, it cannot itself exist in the world of sense. Moreover, it is not fleeting or changeable like the things of sense: it is eternally itself, immutable and indestructible." The Problems of Philosophy, Bertrand Russell P65

[2] Years ago, the late night TV show host and comedian, Johnny Carson, had a recurring bit he did called “Carnac The Magnificent.” One aspect of this but was where he would name 3 seemingly completely unrelated items and then “divine” a way in which they were each (comically) members of a hitherto unconsidered set. A more contemporary version might be this:

My wallpaper

Those Christmas Ornaments

Jerry Epstien

Things that didn’t hang themselves

[3] “That of dividing things again by classes, where the natural joints are, and not trying to break any part, after the manner of a bad carver.” Plato, Phaedrus 265e)