Vallicella has a post here about my post here. Of my argument he says “this is a terrible, a thoroughly and breath-takingly rotten, argument which is why no one in the literature (to the best of my knowledge) has ever made it.” Don’t hold back, Bill!
Actually my argument has a close affinity to Frege’s argument against the correspondence theory of truth, but never mind. Let’s restate it. Let’s suppose that any sentence of the form “S phi's” has a truthmaker. But that truthmaker cannot be S itself, for the reasons Vallicella adduces in an earlier post. If I understand his argument, it is that if phiis ‘sits’, it is contingent whether Socrates is sitting or not, so the truthmaker for ‘Socrates is sitting’ cannot be Socrates himself.
That is his argument. I merely extend it to the verb ‘exists’. Let phi be ‘exists’. Since it is contingent whether any object (apart from God) exists or not, it follows – if Bill’s argument is valid – that the truthmaker T of ‘S exists’ is different from S itself. And then we get an infinite regress, for ‘T exists’ must also have a truthmaker. By equal reasoning, the truthmaker U of that sentence must be different from T, and so on.
I am not saying that Bill’s argument is valid. I am saying that, if it is valid, then equally my argument is valid, unless he shows how the verb ‘exists’ differs in any way from verbs like ‘sits’. Which I don’t think he has done.
He might argue that ‘exists’ is not a predicate, whereas ‘sits’ is. I reply, it is a predicate. ‘- exists’ is satisfied by Obama, but not by the Tooth Fairy. Perhaps there are other arguments that would justify his conclusion. But the point is, he has to give one.
Another argument against truthmakers is that if ‘it will rain on Friday’ has a truthmaker, then it must be a presently existing truthmaker (for the sentence, if true, is true now). So, today being Thursday, the truthmaker for ‘it will rain on Friday’ exists now. By the same reasoning, it had a truthmaker yesterday, given that if ‘it will rain on Friday’ is true today, the same sentence must have been true yesterday. But we cannot change the past. Therefore, if truthmakers for future tense statements exist we cannot determine what happens in the future. But we can determine what happens in the future. Therefore there are no truthmakers for future tense statements, and if so, what reason is there to believe they exist at all?