A Millian about proper names holds that the meaning of a proper name is exhausted by its referent. Thus the meaning of 'Socrates' is Socrates. The meaning just is the denotatum. Fregean sense and reasonable facsimiles thereof play no role in reference. If so, vacuous names, names without denotata, are meaningless.
Presentism, roughly, is the claim that present items alone exist. This implies that no past or future items exist in the sense of 'exists' that the presentist shares with the eternalist who maintains that past, present, and future individuals all exist. What exactly this sense is is a nut we will leave for later cracking.
Now Socrates is a wholly past individual: he existed, but he does presently exist. It follows on presentism that Socrates does not exist at all. The point is not the tautology that Socrates, who is wholly past, does not exist at present. The point is that our man does not exist, period: he is now nothing at all.
We now have the makings of an aporetic pentad:
1) 'Socrates' has meaning. (Moorean fact)
2) The meaning of a proper name is its referent. (Millian thesis)
3) If a name refers to x, then x exists. (Plausible assumption)
4) 'Socrates' refers to a wholly past individual. (Moorean fact)
5) There are no past individuals. (Presentism)
It is easy to see that the pentad is logically inconsistent: the limbs cannot all be true. Which should we reject?
Only three of the propositions are candidates for rejection: (2), (3), (5). Of these three, (3) is the least rejectable, (5) is the second least rejectable, and (2) the most rejectable.
So I solve the pentad by rejecting the Millian thesis about proper names.
You might budge me from my position if you can give me a powerful argument for the Millian thesis.
Here, then, we have an 'aporetic' polyad that is not a genuine aporia. It is soluble and I just solved it.
The Recalcitrant Ostrich will probably disagree.