I have been defending the real distinction between essence and existence in contingent beings. Lukas Novak, though not rejecting the distinction, finds my arguments wanting. Here is his latest challenge to me:
1) First I will use your own weapons against you. The following triad is inconsistent, any two propositions entail the negation of the remaining one. Which limb do you reject?
a) Necessarily, Socrates exists iff Socrates is a man.
b) Possibly, Socrates does not exist.
c) Necessarily, Socrates is a man.
Yes, the triad is inconsistent. I am tempted to reject (c). Socrates is essentially a man, but not necessarily a man. In terms of possible worlds: Socrates is a man in every possible world in which he exists, but, being contingent, he does not exist in every world. So he is essentially a man but not necessarily a man. God, by contrast, is both essentially divine and necessarily divine: he is divine in every world in which he exists, and he exists in every world.
But if I reject (c), how can I claim, as I have, that while Socrates is possibly nonexistent, he is not possibly non-human? For if S. is not possibly non-human, that is equivalent to saying that he is necessarily human, which in turn is equivalent to (c).
Novak appears to have refuted my contingency argument for the real distinction.
2) When interpreting the modalities in your two sentences, one can interpret the implicit quantifications over possible worlds as comprising either all possible worlds, or just the possible worlds where Socrates exists at all.
Lukas is referring to the following two sentences, the first of which I claimed is true, and the second of which I claimed is false (because Socrates is essentially a man):
A. Socrates exists & Socrates is possibly such that he does not exist.
B. Socrates is a man & Socrates is possibly such that he is not a man.
I say that in order that (A) be true, it must be interpreted so that "possibly" invokes quantification over all possible worlds, not just those where Socrates exists (because there is no possible world among those in which Socrates exists such that Socrates does not exist in that world). On the other hand, in order that (B) be false, the quantification implicit in the "possibly" must be restricted to those worlds only where Socrates exists. Because it is not true that Socrates is human in worlds where he does not exist at all. As you yourself concede, essence without existence is just nothing, so in a world where Socrates does not have existence, he neither has his essence, which is humanity. Thus the different modal behaviour of the sentences is merely apparent, it is a result of your tendency to interpret the quantification implicit in modal terms differently when speaking about existence and about essential predicates.
Novak's very powerful objection, in effect, is that the following are both true:
A* There are possible worlds in which Socrates does not exist
B* There are possible worlds in which Socrates is not human
and that these are the same worlds. What's more, the starred sentences are the only possible readings of my (A) and (B). Since the starred sentences are both true, my contingency argument for the distinction between individual essence and existence in Socrates fails. What I had argued is that, since Socrates is possibly nonexistent, but not possibly non-human, his existing is not identical to his being an instance of humanity.
Novak's point could also be put as follows. In every possible world in which Socrates exists, he is human, and in every world in which he is human, he exists. Hence there is no world in which he has the one property but not the other. Existing and being human are therefore necessarily equivalent, equivalent across all possible worlds. If so, it is not the case that Socrates is possibly nonexistent, but not possibly non-human.
I grant the necessary equivalence, but deny that one can infer the identity of existing and being human from it. Necessary equivalence does not entail identity. Triangularity and trilaterality are necessarily equivalent but non-identical.
But this doesn't settle the matter. Lukas could agree that, in general, necessary equivalence does not entail identity, but still claim that I have not given a compelling reason for thinking that existing and being a concrete instance of humanity are non-identical. After all, he is not rejecting the real distinction, but arguing that I haven't proven it.
Despite the obvious force of Novak's argument, I think there is a way of construing 'Socrates is possibly nonexistent, but not possibly non-human' that evades the argument. Here goes.Suppose we take 'Socrates' to refer to a concrete individual essence, one that, obviously, exists. We can say, with truth, that this essence might not have existed, that its nonexistence is possible in the sense that there is nothing in this essence to insure (entail) that it exist. But it is also true that this existing individual essence, this existing instance of humanity, could not have been anything other than an instance of humanity: it could not have been an instance of any other nature, felinity, say. The Socratic essence could not have been a feline essence. Understood in this way, it seems to me true to say that Socrates (the individual Socratic essence) is possibly nonexistent but not possibly non-human. But if it is not possibly non-human, then it is necessarily human, in which case the individual Socratic essence is to be found in every possible world.
This essence must have some ontological status, and indeed a necessary ontological status. But we have to avoid reifying it. We can say that is has a merely intentional status in those worlds in which Socrates does not exist. That is, it exists only as a divine accusative in such worlds. In such worlds the essence possesses esse intentionale but not esse reale. In those worlds in which Socrates exists, the Socratic essence posseses both esse intentionale and esse reale.
We can remove the contradiction in the original triad without hypostatizing essences by ascending to a higher viewpoint: we bring God into the picture. God is a necessary being, so all the essences that enjoy esse intentionale in his mind are necessary beings. To some of them such as the Socrates essence he superadds existence. Although it is false that, necessarily, Socrates is human, it is true that, necessarily, the Socratic individual essence includes humanity.
But then it seems that the real distinction stands and falls with the doctrine of divine creation.