Thursday, April 25, 2019

The analogy of being and the moving spotlight theory of time

On moving spotlight theories, eternalism is true: past, present and future things all exist. But the present is metaphysically special: you have not said all that is to be said about temporal reality if you just said what happens at which times, and how the times are related by relations like earlier-than and simultaneous-with, without having said which time is objectively present. The puzzle for moving spotlight theories is to say what makes the present special.

Here is a start of a moving spotlight theory. Start with the Thomistic insight that there are multiple ways of existing. For instance, God doesn’t exist in the same way in which we do. Now add that temporal beings have three ways of existing: existing pastly, existing presently and existing futurely. Thus, we have at least four ways of existing: divine existence as pure act, past existence, present existence and future existence. These are genuinely different forms of existence, but they are all analogous. And we further subdivide the three temporal ways of existing into substantial and accidental existence.

Moreover, interestingly, these ways of existing can occur in various combinations. For instance, I exist pastly, presently and futurely. An object in the last moment of its existence exists pastly and presently. An object in the first moment of its existence exists presently and futurely. At the first moment of the Incarnation, the Second Person of the Trinity existed as pure act, as well as both presently and futurely. Right now, the Second Person of the Trinity exists in each of these four ways of being.

So what sets out the present as special is this: an event is present provided that the substances and accidents making up the event exist in present ways of existing.

This is eternalism and not presentism, but it captures one central insight of presentism: that to exist presently is different in kind from existing pastly or futurely. It escapes the three horse argument against presentism by saying that the real horses exist analogously to each other but the unreal one does not exist at all.

Of course, this is only a start. It would be nice to be able to say something substantive about how the three temporal ways of existing differ from one another. I don’t know that this can be done, and I don’t particularly want to pursue this, since I much prefer the elegance of the B-theory of time.


Atno said...

I think probably the biggest reason many Aristotelians are attracted to A theory is that it seem to make the best sense of change and the act/potency distinction, which is a fundamental part of both Aristotelian and Thomistic philosophies. It would be very interesting to see how you understand the distinction, whether you agree with it, or think it would work in B theory, etc.

It is also interesting to note that the act/potency distinction is also strongly related to PSR; I suppose a lot of people (especially Aristotelian philosophers) who take PSR to be intuitively plausible or self-evident understand it in terms of act/potency: that a potential cannot be actualized without something that actualizes it, and any existing contingent thing (or contingent fact that holds) is but an actualized potency. So this subject is quite important for natural theology, as well.

Alexander R Pruss said...

I don't talk of act/potency myself. I prefer talk of causal powers and their actuation.

That said, I find it hard to see what the classical Aristotelian can say about act/potency that the B-theorist can't give an analogue of. Let's say that I now have a mere potential for getting up. Presumably this is not a mere potential for getting up right now, but for getting up in the future, as I am not actually getting up right now. So, the B-theorist can say: at t1 I have a mere potential for getting up at t1. Where is the difficulty?

Admittedly, if I do in fact get up at t1, then it is eternally and unchangingly true that I get up at t1. But esentially the same is the case on the A-theory (unless one accepts an open future, which is incompatible with classical theism): it is eternally and unchangingly true that I did, do or will get up at t1.