Existence, Predication, and Kant
Some say the quantificational view of existence — which roughly equates existence to number — traces back to Kant. This is misleading. Before seeing why, let’s get straight on what the quantificational view of existence is.
For many analytic philosophers, existence is not something predicated of individuals, but of concepts. To say, for example, that cats exist, is just to say that the number of the kind cat is not zero = that there is at least one thing such that that thing is a cat. This analysis of existence forces such philosophers to say that language which seems to predicate existence of individuals — for example, that Socrates exists — is misleading.
Another way of putting the quantificational view of existence is this: existence is instantiation of concept. To say cats exist is just to say something instantiates the concept cat. At least one thing, maybe more.
Now, some suppose this analysis of existence — which is definitely false, as Barry Miller shows — is Kant’s position. But this, I suggest, is a misunderstanding. While it is true that Kant didn’t think existence was a real predicate, that does not mean that Kant thought existence couldn’t be predicated of individuals. So, what’s going on, then?
The answer is this. For Kant a real predicate is something that enlarges the concept of the subject. It is, in other words, a determining predicate, which increases the intension of its subject which reducing its extension.
To wit, “Being is evidently not a real predicate, that is, a conception of something which is added to the conception of some other thing.”1
For example, when I predicate black of dog, I am characterizing the subject in some definite way, thus causing it to differ in content than if I just said dog. Kant argues existence does not do this, since it does not enlarge the content of whatever subject it is predicated of. For Kant, then, if a real predicate must enlarge the content of whatever subject it is predicated of, and if existence does not do this, then existence is not a real predicate. However, it is a non-sequitur to think this meant Kant had a modern analytic view of existence, supposing existence could not be said of individuals at all, but only of concepts.
False.
Surely, we can say “Socrates exists”, which predicates existence of the individual subject without enlarging its content. How so? Well, because existence is not a what determination in most instances. Existence is a whether determination.
From Immanuel Kant, The Critique of Pure Reason, IV, trans. J. M. D. Meiklejohn, at Project Gutenberg (26 July 2021), at Gutenberg.org.