The blog of Dr Glenn Andrew Peoples on Theology, Philosophy, and Social Issues

Nuts and Bolts 008: Nominalism


In the “nuts and bolts” series, I explain and discuss some of the fundamental ideas in philosophy (and theology sometimes) that are taken for granted within the discipline, but which might not be very well known to ordinary human beings. This time the subject is nominalism.

Do tables exist? Do all red apples (assuming that apples exist) have something called “redness” in common? These might strike most people as pretty weird questions, but questions like these are at the heart of the distinction between realism and nominalism. They’re both ways of addressing the problem of universals. We classify things all the time; as circular, as yellow, as an elephant, as a mountain, as a snail, as wooden, as evil, and so on. Nominalism and realism are alternative ways of thinking about what we’re actually doing when we classify things this way. I’m going to be zooming in on nominalism here, but I’ll be simplifying heavily in the spirit of only attempting to provide the nuts and bolts, without going into a whole lot of depth.

According to nominalism of a pretty stark kind, there really are no tables or chairs, red apples don’t have the quality of “redness” in common, and two cats don’t really belong to one species. That sounds like a pretty bizarre collection of claims to people who are just encountering nominalism for the first time. Let’s pick on the example of tables. Imagine that you have two tables in a room. One is a large, twelve-foot-long, grand oak banquet table, and the other is a round glass-top coffee table, just two and a half feet in diameter, with a wrought iron frame.

What do these two things have in common? They’re not made of any of the same materials. They aren’t the same shape, and they’re not even close to being the same size. But even if we had two banqueting tables, what would they have in common? The strong realist answer is to say that there exists a universal, or to use the language of Plato, there exists a form of a table, the ideal table that exists in the world of forms or ideas, and something is a table if it participates in this form, if it resembles the ideal table. But for a materialist, there is no “world of forms” out there because the world of forms is not material. There’s no universal “table” that other tables can resemble. Instead, there are various constructions out there that we’ve decided to call “table” and use in a certain way. They resemble each other (if not in appearance, at least partly in usage) rather than some idea of a table, there’s no overarching category of table that they belong to, there’s just a naming convention and that is that (the Latin term nomen means “name,” and nominalis means “of or pertaining to names”). The same is true of colour. There’s no universal form of “redness” out there that things have or lack. There’s just a collection of physical properties that cause our minds to form the judgement “that is red.” The same is true of cats – there really is no species to which they belong, there are just individuals that we call the same thing if they have features in common. Another way of stating this is that there’s no property of redness, or table-ness, cat-ness or anything like that. Properties imply abstract objects, and nominalism will have none of that. The only objects out there are concrete material objects. Some medieval thinkers (the best example being Augustine of Hippo) were realists but certainly did not believe in a “world of forms.” Instead, there existed in the mind of God ideas of the ideal X, where X could be anything from a table to an aqueduct to (in the modern world) a steam engine to a turbine. To the extent that a thing participates in or resembles this idea, it belongs to the category exemplified by that ideal (this view is often called “conceptualism”). But again, if one is a pure materialist then there’s no God either, so this is not a live option. I should add, however, that one certainly doesn’t have to be a materialist to be a nominalist, and vice versa. William of Ockham, after all, was both a devout Christian and a famous nominalist.

Peter Van Inwagen suggests a useful example that illustrate the problems that a thoroughgoing nominalist faces in everyday life (bear in mind that a “problem” as I use that term is not necessarily a fatal objection. It is merely a hurdle to be negotiated, possibly successfully, possibly unsuccessfully). Consider the belief:

Spiders share some of the anatomical qualities of insects.

This is a belief that most people probably hold, whether they consider themselves to be a nominalist or not. But surely this rather innocuous belief supposes that there are properties and categories of the sort that a nominalist cannot accept. Van Inwagen goes on:

How might a nominalist respond? Suppose we present this argument to Ned, a convinced nominalist (who believes, as most people do, that spiders share some of the anatomical features of insects). Assuming that Ned is unwilling simply to have inconsistent beliefs. there would seem to be four possible ways for him to respond to this argument:

  1. He might become a platonist.
  2. He might abandon his belief that spiders share many of the anatomical features of insects.
  3. He might attempt to show that it does not after all follow from this belief, that there are anatomical features.
  4. He might admit that his beliefs (his belief in nominalism and his belief that spiders share some of the anatomical features of insects) are apparently inconsistent, affirm his nominalistic faith that this inconsistency is apparent, not real, and confess that, although he is confident that there is some fault in our alleged demonstration that his belief about spiders and insects commits him to the existence of properties, he is at present unable to discover it.1

Again, the point here is not that there’s no way out for the nominalist (Van Inwagen notes that the nominalist is most likely to choose option 3, difficult though the argument will be to make.

At an even deeper level, is it even true to say that there are two objects here? If there’s no universal object of “table” to resemble, surely there’s no way to measure that we have an object that counts as a thing that resembles it. Maybe all we have is a collection of particles arranged in a “table-like way,” and it’s just a convention of language that calls this arrangement one object? The more you’re inclined to think this way, the more of a nominalist you are.

Maybe you find nominalism a little counter-intuitive. Maybe the distinction between realism and nominalism is just not something that has occurred to you before. Maybe in spite of the initial weirdness of nominalism, your outlook is firmly materialist, there’s no God (and so no mind of God), and there’s just no way to account for universals and so you need to grit your teeth and accept nominalism even though it seems a bit strange to you. Or maybe it doesn’t seem strange at all, and now you have a name for the view that your already held anyway.

Glenn Peoples

  1. Van Inwagen, “Introduction: What is Metaphysics?” in Peter Van Inwagen and Dean Zimmerman (ed.), Metaphysics: The Big Questions (Oxford: Blackwell, 1998), 9. []


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Flannagan v Bradley


  1. beryl

    Interesting subject and a good introduction to it. Thanks for writing it up.

    “Nominalist,” to someone like me who has thought very little about it, seems like a label that a frank nominalist-in-practice wouldn’t willingly give to him/her self. “How can I call myself a nominalist if there is no such thing as a universal form or idea of Nominalist?”

    “Nominalism share some of the philosophical qualities of philosophy X” — this would cause a nominalist the same problems as the spider/insect problem, wouldn’t it? Recursive metaphilosophy gives me a headache 😉

  2. Deane

    The whole discussion of this ‘problem’ (problems not existing in reality, hence the scare-quotes!) always seems to get more complicated than clear when we talk about the existence of ‘universals’. I always prefer talking simply about correspondence between our ideas and reality. The (non-)existence of ‘universals’ just seems to add a layer of unnecessary obfuscation.

    What do I think? I’ll give you a clue. There are no triangles in reality, but one can realistically point to a triangle in reality. 😉

  3. Deane, I think it’s possible (read: probable) that without realising it a lot of people talk about “our ideas” (your term) where that phrase is functioning in exactly the same was as a universal. They use universals while denying it.

  4. Deane

    Well yeah, but ‘universals’ brings up a lot of medieval metaphysical baggage best ignored. I’m not saying the discussions had no value, just that there are more simple ways of addressing the underlying issue, which only sounds problematic when it gets translated into the ‘existence or nonexistence of universals’ debate. If, on the other hand you explain to people that our ideas do and don’t correspond to reality at the same time (more or less ‘moderate realism’), most people exposed to a bit of social constructionism get the issue, without being bogged down in the historical nominalist-realist debates.

  5. Right, because platonic idealism is complex and hard, whereas “social constructionism” is ordinary and everybody gets it. 😉

  6. Hi Glen and thanks for the interesting article.

    I’ve recently been engaged in conversations regarding various stances in relation to universals and, after a bit of research decided that I was more closely aligned to conceptualism than anything else. I was working off this definition of conceptualism.

    In furthering my education on the topic I came across this blog entry. But I notice that you appear to be working from a different definition when you say,

    To the extent that a thing participates in or resembles this idea, it belongs to the category exemplified by that ideal (this view is often called “conceptualism”). But again, if one is a pure materialist then there’s no God either, so this is not a live option.

    As a summary, I believe that a sufficient explanation can be found in the view that everything is made of physical stuff and that real-world objects can be simulated or represented–often imperfectly–in physical minds. That no supernatural entity or realm is required and that ‘abstract objects’ are really just another layer of abstract concepts (which, once again are physical configurations of neurons).

    Can you go into a little more detail how you see conceptualism working and why it ought not be ‘a live option’ to a materialist?

  7. (Sorry, that should be ‘Glenn’. My bad.)

  8. Damian, if someone had simply offered the part that you quoted, and concluded that it isn’t a live option for a materialist, I’d be confused too!

    That conclusion would only make sense if they included a bit more context, as your quote leaves out the crucial part. Here:

    Some medieval thinkers (the best example being Augustine of Hippo) were realists but certainly did not believe in a “world of forms.” Instead, there existed in the mind of God ideas of the ideal X, where X could be anything from a table to an aqueduct to (in the modern world) a steam engine to a turbine. To the extent that a thing participates in or resembles this idea, it belongs to the category exemplified by that ideal (this view is often called “conceptualism”). But again, if one is a pure materialist then there’s no God either, so this is not a live option.

    It makes more sense now, right? Of course if one doesn’t believe in God, they can’t believe that something exists in the mind of God.

    or (OK, this second link doesn’t refer to the mind of God, it only refers to examples like Peter Abelar or William of Ockham, but if the reader knows who those people are, he will realise that this is what they thought.

    So that view is – as I indicated – often called conceptualism. Are there versions of conceptualism that purge themselves of that historical baggage? Sure.

  9. Ah, right, so in your opinion a pure materialist *can* hold to conceptualism (just not necessarily the kind in the example held by some medieval thinkers)? And that nominalism is not the only valid option open to materialists?

  10. Well, people can re-tool conceptualism into a modern variety. However, they’d have a difficult job maintaining that it’s not, at bottom, some form of nominalism after all.

  11. Cheers Glenn.

  12. Ok, I’m a bit like Damian in that I’m reading this trying to work out what name to give my intuitive take…

    And I really can’t see the problem the spider example holds for a nomalist. I don’t think there are abstract objects, or that properties ‘exist’ independently of the physical objects that we think have them. When I say spiders and insects share anatomical features I’m really just saying the compound eyes of spiders and insects resemble each other, and they are part of a larger set of objects “anotomical features” which we group together because they too resemble each other. The properties themselves don’t exist (in another world ‘compound eyes’ might not have evolved, but brains that would have grouped them together could have. Then you have an abstract object explaining properties which didn’t exist. Which seems very odd to me) they’re just a useful way for our brains to organise the world.

    So, what am I missing?

    (This is particularly odd to me, because I’m very much a ‘species realist’ in the debates biologists have abuot species, but I guess the terms are used slightly differently in that debate than the over-arching philosophical)

  13. David, I think it’s common for people to be realists without realising it. For example, it’s pretty normal, I would surmise, for people to presuppose the existence of properties while at the very same time believing that one believes in no such thing.

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