Universals: Realism vs. Nominalism

Hello everyone. I’m new here, so please call me out if this post is in the wrong place or there are already active threads on this subject.

I’ve been reading about Metaphysics in the Anglo-American tradition recently, and one thing that particularly struck me were the debates surrounding the nature and existence of universals. I guess I’m interested in how much interest there is in this problem among people studying philosophy, and the sort of solutions people are sympathetic towards.

Of course you might think that Metaphysics in the Anglo-American tradition (broadly speaking, specifying the fundamental entities from which reality is structured) is totally redundant, and ought to be replaced by the sort of alternatives one finds in the Continental tradition, e.g. Heideggerean Poetics, Deleuzian Difference or Badiou’s set theory. I don’t know enough about these ontologies or the questions they set out to properly address the question of whether they offer a more legitimate metaphysical project. Perhaps that could be a separate topic of discussion.

With that qualification aside, let me set out the problem of universals as I understand it, and some of the solutions I’ve come across. Incidentally, David Armstrong’s book called ‘Universals: An Opinionated Introduction’, is a pretty good starting place.

Anyway, I think a good way of getting to grips with the problem is through the token/type distinction. For example, how many words are there on this line:

THE THE

There is a sense in which the answers ‘one’ and ‘two’ are both correct. ‘Two’ is correct if you treat each word as an individual token. ‘One’ is correct if you treat both words as tokens of the same type.

The question is, what is going on when two tokens are of the same type? In the case of our two words, it seems as though there is a sense in which they are identical. But how are we to understand ‘identical’? If we mean it in the strict sense, then there must be some property that both tokens share. And what is a property? Well it seems to be a determinate repeatable, something which can be instantiated at more than one place at the same time.

Perhaps we do not want to allow strict identity between are tokens though, but rather suggest that they are identical in some looser sense. This would avoid talk about this funny thing we called a ‘property’, which could exist at different non-overlapping points in space at the same time.

David Armstrong puts it this way: some things are electrons; most things are not. What is it for something to be an electron, of the type electron?
I think the problem can be more clearly understood if we discuss it in terms of ‘sets’. We can think of an infinite number of sets, but some sets seem to be more natural than others. For example, the set of all electrons seems to have a more natural unity than the set [my computer, a dog, an electron, a tree]. Both are legitimate sets, but the members of one seem to have a lot more in common than the members of the other. So we can ask What distinguishes the sets of tokens that mark out a type from the sets that do not?

A realist about universals would say something like the following. All tokens of a particular type have something in common, a property. Indeed they all have the same property. This is possible because properties are not like particulars. They can exist at more than one place at the same time. They are abstract entities which can be multiply instantiated.

A nominalist would reject this entirely. She would say that the only constituents of the world are particulars. These particulars can be grouped together in certain ways. For example some nominalists say that particulars fall into certain natural sets. It is just a basic feature of the world that such sets exist. Other people say that particulars can resemble each other. Resemblance is a primitve relation that holds between objects and which allows them to be grouped into certain sets. Some other philosophers say that particulars do have properties, but that each property is unique to a certain particular. These properties are often called ‘tropes’. When two particulars are grouped into a particular natural set, it is because one of their tropes resembles each other. Doing things this way round is useful because it allows you to divide things up more finely - you do not just have particular obects, you can talk about particular properties too.

I’m not sure how clear all that is. There are problems with all the different accounts, which I’m happy to go into with people. Personally I’m at a loss. Every Nominalist theory seems inadequate to me, but I can’t get my head around the idea that there are abstract properties which can be instantiated at different non-overlapping points at the same time.

if I understand your question, one could argue that “tokens” are much more than linguistic events…

the words being identical as words is fine because the and the is the… the word’s meaning being identical is a problem for the meaning of “the the” because the first “the” has a slightly different meaning from the second “the”… the first the in the sentence “the the” is used to specify which “the” is being named… the second the labels all members of the class of articles…

I hope that made sense… language is tricky…

but if you think of tokens as concrete instances of a type beside strictly unitary numerical events or language events it may help…

take two coins out of your pocket…

what makes them coins?

they are each tokens of the type coin…

what is each worth?

if they are both nickels, is there a difference between them?

this one is worth 5 cents…

this one was minted in 1927 and is worth thousands of dollars…

are they still both nickles? are they still both “coins”?

most importantly, will you treat them each as if they were identical?

(that was a damn expensive gumball)

-Imp

Yes, sorry, I was just using the two words as an example. It isn’t really a question about linguistics. The two coins are perhaps better, but again it might seem a bit arbitrary because they’re really just lumps of metal we’ve decided to treat as coins, right?

But there seem to be natural types. Like two rocks? Or two electrons, if it makes sense to say that? What about two things with the same property? Like being red? Or weighing 4 pounds?

homo mensura… protagoras…

man is the measure…

those coins are formed lumps of metal… there was another element added to them…

this is a chicken

that is a chicken

are the chickens identical? no

but they are both chickens…

this one is dinner

natural types of chickens?

the chickens themselves don’t understand the difference we put on them…

-Imp

No, they don’t. And I agree that to a degree, what we count as a natural type is dependent upon our interaction with the world. But I’m not sure how that solves the perceived problem, unless you mean to deny the existence of natural types and properties?

I think that duality is necessary.

But.

there are particles (in sub-atomic physics) that are not distinguishable from each other even in theory. Rather than having unique quantum states, they even tend to cluster into identical quantum states, including identical positions.

Question: If two things exist identically, with even the same position, what makes that different from one thing existing with those properties?

Answer: There are two of them.

Physical things are quantifiable, which means that “THE THE” is different from “THE” in that there are two words in the first and one in the second. Two nickles are different from one nickle by a difference of one nickle - it’s not a difference in type, but it is definitely a distinction.

Thanks everyone. I don’t think I’m being very clear though, or people aren’t reading the whole post. This:

was just supposed to be a way of drawing the token/type distinction. The fact that there are one or two words on the line, depending on how you look at it, is not in itself what philosophers who write about this sort of thing are getting at. Its the token/type distinction understood more generally, as it applies to things like properties and kinds.

Perhaps this will help. Imagine that instead or writing two words on the next lines, I am pointing at two objects:

A BUS
A POSTBOX

Now there is at least one property which these two objects share, that of being red. In fact lets say they have the same property (they are exactly the same shade of red). This is the sense in which they are tokens of the same type: they are both objects with the property of being red.

Now what does it mean when two objects have the same property? Do we mean ‘same’ in the strict sense, that there is just one thing, a property, which they both instantiate? And if we do, what is this funny thing that can exist at more than one point in space concurrently and is not reducible to any one of its parts? And if we don’t want to understand ‘same’ in this strong sense, then what exactly is going on when two objects have the same property, or are of the same kind?

The first 100 lines to Plato’s Parmenides are also a pretty good introduction to this problem.

The answer is quite obvious.

the world is one of particulars, meaning all things are different. but when we say things are the same. we mean we are ignoring their differences. one chicken is the same as the other chicken because they are physically the same dispite being spacially different. it goes like this

‘C distinguishes A and B. A and B are the same, ignoring C’

problem solved.

That’s just stating the problem surely? They are different because they are in different places, yes; but you’re allowing that there is a sense in which they are the same. What I’m asking is what it is that you are noticing when you notice this?

Anyway, I think a good way of getting to grips with the problem is through the token/type distinction. For example, how many words are there on this line:

THE THE

There is a sense in which the answers ‘one’ and ‘two’ are both correct. ‘Two’ is correct if you treat each word as an individual token. ‘One’ is correct if you treat both words as tokens of the same type.

the two senses “you” get are actually two different questions.
1- how many words are there on this line?
2-how many different words are on this line?