(Following up on my earlier post on an argument for nominalism in the Elements of Law.)
In chapter 2 of De Corpore Hobbes offers two further arguments for the view that names are the only universals.
(1) The first involves the way in which common names denote.
However a common name, as it is the name of several things taken one by one, but not however of all the things together at the same time (as ‘man’ is not the name of human kind but of Peter, John, and the other men separately) is called for that reason universal. So the name ‘universal’ is not the name of some thing existing in rerum natura, and not the name of an idea, or some phantasm formed in the soul, but is always the name of some vox or name (DeCo 2.9).
This appears to be supposed to be an argument for nominalism. Hobbes’s central point is, to take an example, that ‘animal’ denotes this animal and that animal, and indeed denotes each and every one of the animals, but does not denote any other single thing that somehow stands for all the animals. (Nor does it denote the collection of the animals.)
Why does this show us that ‘animal’, the name, is the only universal thing, and there is no universal animal? I take it that the argument is that if there was a universal thing animal, ‘animal’ would denote it, but it denotes the individual animals, so there is no universal animal.
(2) In the continuation of the above passage from De Corpore, Hobbes raises the issue of what there is in our minds corresponding to common names. There are, he says, “conceptions answering to” universal things in our minds, though as in Leviathan common names are not said to signify those conceptions. The conceptions answering to ‘animal’, for instance, are “images and phantasms of individual animals”. When we hear a universal name, “we remember that vocal sounds of this kind sometimes evoked one thing in the mind, sometimes something else”. So sometimes (every time?) a common name it used it brings an idea of an animal to mind, and at different times it might well bring different ideas to mind. Sometimes when I hear ‘animal’ I think of this cat, sometime I think of that giraffe.
The most important point for Hobbes here, perhaps, is that there is no universal idea that is brought to mind (or signified, or denoted, or named) by ‘animal’. Nor indeed is an idea of a universal object brought to mind. Rather, only particular ideas of individual things come to mind. When we use a universal name, all we think about are particular things, giving us reason to think that aside from the name there are only particular things.
Why should one agree that no universal idea is brought to mind? Hobbes seems to appeal to experience and introspection. If you think, he says, of what comes to mind when you hear the word ‘animal’, you will realize it is only the idea of some animal or other. But why not suspect that, sometimes at least, the universal idea of animal comes to mind?
One might suspect that Hobbes’s argument here is supported by his imagism, like the argument in the Elements of Law. However, Hobbes goes on in De Corpore 2.9 to argue in the opposite direction, from his nominalism to there being only the imagination: because the conceptions we have that relate to general names are only particular ones, then there’s no need to appeal to any faculty other than the imagination here. This is in part an anti-Cartesian point, in that Hobbes takes himself to show we do not need to appeal to an ability to have intellectual insight, via clear and distinct perception, into the natures and essences of things. This is almost the exact opposite of an imagistic argument for nominalism.