This continues the discussion with James Anderson. See the comments to the related article below. Here is Professor Anderson's latest comment with my replies.
So are you saying that prior to the time Socrates comes into existence the proposition It is possible that Socrates come into existence doesn't exist at all?
Yes, if either Socrates himself, or an haecceity property that deputizes for him, is a constituent of the proposition in question. For it is surely obvious that before Socrates came to exist, he did not exist, and so was not available to be a constituent of a proposition, a state of affairs, or anything at all. As for the putative property identity-with-Socrates, I have already shown to my satisfaction that there cannot be any such property if properties are necessarily existent abstract objects.
No, if we think of 'Socrates' along Russellian lines as a definite description in disguise replaceable by something like 'the most famous of the Greek philosophers, a master dialectician who published nothing but whose thoughts were presented in dialogues written by his star pupil and who was executed by his city-state on the charge of being a corrupter of youth.' I have no objection to saying that, prior to the time Socrates comes into existence, the following proposition exists: It is possible that some man having the properties of being famous, Greek, etc, come into existence.
Are you thereby committed to the contingent existence of propositions?
Not across the board.
Or would you favor full-blown nominalism about propositions?
Not at all. Here is an argument for propositions that impresses me.
Here's my reasoning laid out step by step. Perhaps you can tell me where you would want to jump out of the cab.
1) Socrates came into existence at t.
2) It is possible that Socrates come into existence at t. [actuality entails possibility]
It is a modal axiom that everything actual is possible. So of course actuality entails possibility. But it doesn't follow that before Socrates came into existence, that he, that very individual, was possible. For it might be that he, that very individual, becomes possible only at the instant he becomes actual. If a thing is actual, then it is possible; but that says nothing about when it is possible.
3) The proposition It is possible that Socrates come into existence at t is true. Call this proposition P. (P is a tenseless proposition, although it makes reference to a particular time.)
You are moving too fast. Yes, the proposition P is true. But that P is tenseless is a further premise of your argument and should be listed as such and not introduced parenthetically. Can you prove that P is tenseless? It is not obvious or a non-negotiable datum.
I grant that there are tenseless propositions. Whales are mammals. Numbers are abstract objects. 7 plus 5 is 12. The same goes for their negations. But one cannot assume that every proposition is tenseless. (I grant that every Fregean proposition is tenseless, but that is a technical use of 'proposition.') It might be that P is true only at t and at times later than t.
4) P is necessarily true. [by S5]
Not if P is true only at t and at times later than t. Does this violate S5? Not obviously. On S5, Poss p --> Nec Poss p. Can it be shown that 'p' here includes within its range propositions of de re possibility such as P?
5) P is true at all times. [because necessary truths cannot fail to be true]
6) P is true prior to t (i.e., before Socrates comes into existence).
7) Prior to t, it is possible that Socrates come into existence (at t).
I have given reasons to deny each of these propositions.
At the very least, we have a stand-off here. Professor Anderson has not proven his point. Perhaps I cannot prove my point either. Then we would have an aporia.