Plantinga on Negative Existentials
I won’t waste much time reviewing this issue which is pretty much a poster child of what Bacon was referring to when he spoke of "…subtile, idle, unwholesome and (as I may term them) vermiculate questions.…" (The Advancement of Learning, p.140) Anyone who needs background can consult Chapter VII of The Nature of Necessity. Let me just observe that Plantinga's conclusion cum solution is just absurd on the face of it. For he asserts that a negative existential, if true, expresses a different proposition than it would if it were false. One consequence of this absurdity is that:
(1) ¬(Socrates exists)
(2) Socrates does not exist.
could have different truth values. To hide the absurdity Plantinga pulls a little accounting trick. He says that (1) "obviously" means:
(3) "Socrates exists" is not true,
pulling that old Dark Ages trick of throwing in a lot of Latin to muddy the waters. If an accountant perpetrated this sort of fraud with an annual report, he'd be indicted. (1) is not equivalent to (3). It is equivalent to
(4) It is not the case that Socrates exists.
Even if (1) could be reconstructed as (3) and assuming that existence is a predicate, which it is not, then, on the basis of Plantinga's conclusion, the following metalinguistic equivalence is or could be false:
(5) "Socrates exists" is true if and only if Socrates exists.
I've got some Latin for you: Bullshitio priestimus faggotendum.