Presentism, Truthmakers, and God's Memories: Reply to an Objection

I've argued here that the truthmaker objection to presentism is best met by appealing to God's memories of the past as the truthmakers of true propositions about the past. (Note: Readers of the linked paper should be aware that I am still revising it. Constructive feedback is welcome.) Instead, I will briefly explain how my proposal is supposed to work and then I'll present an objection sent to me by Patrick Todd, a grad student at the University of Missouri who independently arrived at the same idea, but found that it was not well received by his colleagues.

First, the basic idea is this: Truths about the past need truthmakers, some parcel of reality the existence of which grounds and, thereby, makes those truths true. This poses a prima facie problem for presentism, which is the view that whatever exists, exists now, in the present. Somehow the presentist needs to supply presently existing facts to make true every truth about the past, but it's not at all obvious how this could be done. What present fact, for example, could make it true that Columbus discovered American in 1492? Presumably it would have to be some sort of causal trace of that past event, but the available physical evidence is not sufficient to guarantee the truth of that event. The same goes for every other contingent truth about the past.

Enter God's memories. A presentist who is prepared to accept theism has, I think, a relatively straightforward answer to the truthmaker objection. First of all, the combination of theism and presentism requires that God exist now, not atemporally. Hence, God was present in 1492 and directly experienced Columbus's voyage. As omniscient, God retains a perfectly detailed memory of that event as a consequence of his experience of it, even though the event itself no longer exists. God's memories, therefore, contain presently existing traces of that past event and every other past event. Those memories represent past events in full detail in the exact sequence in which they occurred. And since those memories would not have been what they are if past events had not occurred as they did, those memories suffice to guarantee the truth of every true proposition about the past.

Now for the objection. I'm quoting the email I received from Patrick here:

They said that the position leads to a severe Euthyphro problem:

Is p true because God remembers that p, or does God remember that p because 'p happened' is true? Or, said differently and more simply, Is it true because God remembers it or does God remember it because it is true?

[...] On the one hand, if we say that X is true because God remembers X, then it looks like God could just remember any old X and it would be true that X. ... And on the other, if we say that God remembers X because "X happened" is true, then it looks like there is some past state of affairs to which God's memory presently corresponds. And in that case, we haven't solved the grounding problem.

Here's my reply. Let P be the present-tense proposition "Columbus discovers America". We can then represent the past-tense "Columbus discovered America" (or, alternatively, "It was the case that Columbus discovers America") as WAS(P). Let Q=WAS(P). And let T be the present state of affairs that serves as the truthmaker for Q.

The proposal on the table is that T is one of God's memories. The important question is which memory? Here's where the Euthyphro-type objection as formulated above goes wrong. The truthmaker for Q cannot be God's memory that Q. Why not? Well, to remember something is to represent it as being past, which is like tacking on a past-tense operator, WAS(). So, since Q = WAS(P), if God remembers that Q, then he remembers that WAS(P), which means the representational content of God's thought becomes WAS(WAS(P)), a past-perfect construction. But God's memory of P has the representational content WAS(P), a simple past construction. Since WAS(P) = Q, that's what we want.

So T = God's memory that P = God's belief that WAS(P) = God's belief that Q.

(I realize that memories cannot in general be equated with past-tense beliefs, but for God this seems unproblematic. He has directly experienced and thus remembers every past event, and he has past-tense beliefs about every past event. Hence, God's memories and past-tense beliefs are coextensive.)

A possible rejoinder at this point is a refomulation of the Euthyphro-type dilemma: Is (a) it true that Q because God believes that Q, or (b) does God believe that Q because it is true that Q?

On the view I'm defending, (b) gets things explanatorily backwards. It is God's memories, or if you prefer his past-tense beliefs, that make true propositions about the past true. So I must reject (b). The objector might wonder, though, if it is not I who have things explanatorily backwards. Doesn't God believe what he believes because it's true? To that I say No. God doesn't believe anything because it is true. Rather, God believes what he believes because he is immediately acquainted with the reality that makes it true. (For my defense of this claim and some discussion go here.)

What about (a)? The worry is that this could render God's beliefs about the past arbitrary, such that God's could just concoct some story about the past, convince himself of it, and thereby make "true" propositions about a past that never was. But it should be obvious that this worry is misplaced. God's beliefs about the past cannot be arbitrary because, in the first place, they are themselves causal traces of the past--God's belief that WAS(P) is a causal trace of the very event that made P true when P was true, namely, the event of Columbus's discovering America. And, in the second place, because God is essentially omniscient, he could not have believed WAS(P) otherwise. So this version of the Euthyphro-type objection fails as well.