A foundational commitment of Aristotelian philosophy is that all facts are grounded in what substances and features intrinsic to substances, namely forms and accidents, exist. But it is possible for the past to have been different without there being any difference in what substances and features intrinsic to substances presently exist. Therefore, the Aristotelian cannot equate present existence with existence.
In other words, Aristotelians cannot escape the standard grounding arguments against presentism.
Objection 1: A theistic Aristotelian can ground facts about the past in features of God (say, God’s memories).
Response: Only if God is mutable. And there are good reasons to believe that if God exists, he is immutable.
Objection 2: Past events affect present substances in various ways.
Response: There is a possible world with laws of nature similar to ours that starts at time 0 with nothing but two material causally isolated substances A and B (and God, if theism is true) that wiggle around in indeterministic ways. A month later, substance A ceases to exist (maybe God stops sustaining its existence), and no new substances come into existence. Now, in month 2, there is only one substance B. Since the two substances were causally isolated, substance B is not affected in its intrinsic features by anything that substance A did. Thus, the facts about how substance A used to wiggle about are not grounded in the intrinsic features of material substances in month 2. (If one says that we regain grounding when we take God’s intrinsic features into account, that will take us back to Objection 1.)
One might respond that complete causal isolation is impossible. But that’s not right. For imagine that, like in our world, causal influences cannot propagate faster than at the speed of light, and A and B start off one light-year apart, and while A perishes after a month, B perishes after six months. Then B is not going to be affected by A’s wiggles.
Objection 3: But maybe there has to be some kind of a metaphysical influence whereby all present substances are affected by all past substances.
Response: This is not plausible in light of the response to Objection 2. But let’s grant it. Then I transpose my argument to the future. Obviously, future contingent events don’t normally (apart from supernatural cases, like prophecy) affect how substances presently are. Hence even if we grant the mysterious metaphysical influence of past substances on present ones, we still have a problem about the future. That problem could be solved if we embraced an open future, as Aristotle did, but we shouldn’t follow Aristotle in that.
18 comments:
Have you talked with Edward Feser on this subject? He is an Aristotelian presentist, and his response to Vallicella indicates that he denies that facts about the past are grounded in presently existing forms and accidents.
I think Ed has abandoned what I consider to be *the* central insight of Aristotelianism, namely that the substances are the fundamental existents and that everything else is their accidents. Of course, that doesn't mean that Ed is wrong: the central insight of Aristotelianism could be wrong instead.
Or it could be that Ed has abandoned a less central tenet, that truth is grounded in being.
Dr. Pruss
Do you think that Eternalism is less costly then presentism? It seems absurd how change is analysed as succession of states on B-theory. How can an aggregate of something static amount to change?
As Graham Priest remarks in critique of Russel's At-At account of motion "How can a going somewhere be composed of an aggregate of going nowheres?"
Red:
On the at-at theory with continuous time, change is grounded in a sequence of instantaneous states. An instantaneous state is not static. Static things endure over a period of time.
That said, I don't accept the at-at theory any more: http://alexanderpruss.blogspot.com/2018/08/bilocation-and-at-at-theory-of-time.html
But it does seem static in the sense that there isn't any intrinsic state of motion at each instant in the sequence.At each instant the moving body is indistinguishable from a body at rest. So how can an aggregate of such states amount to motion?
And it also seems that something that don't endure over a time period could still static, like if the world consisted of a single instant only.
Spit-balling here, but I wonder if we can generate another problem for presentism. Does presentism entail that God is within time, namely some present moment? While Augustine and others think the "now" of the present is an icon or reflection of eternity, it would be odd to think God exists within the present moment we also experience, as a contained thing within a container or a bounded thing falling within a boundary. But it seems like presentism is a claim about whatever exists existing only within the present moment. This would seem to require that God only exists if He is within time. Then, presentism might entail other problems for theists of a Thomistic ilk.
Red:
How is the moving body distinguished from a body at rest given presentism? There are two main options. Either (a) there is a primitive property of being in motion or (b) the moving body is in a location where it didn't use to be. But option (a) is something the eternalist can adopt just well. And option (b) is just a tensed formulation of the at-at theory.
StMichael:
The typical Thomistic presentist will deny that God exists within the present moment. I go back and forth on whether the Thomistic presentist is consistent in that denial.
I think presentist should think of such property as Potentiality. There might be some doubt as to how it can be accommodated within presentism but it doesn't seem compatible with Eternalism at all.At least from what I understand.
But a potentiality for movement isn't the same as movement. I suppose, though, movement could be seen as an actualization of a potentiality for movement (though this sounds circular).
However, the eternalist can just as much say that at time t0 there is a potentiality for movement which is actualized at time t1. This doesn't seem any different, except for tense, from what the presentist will have to say about past movement: at 8:59 am (before I headed off for work) there was a potentiality for movement which was actualized at 9:00 am (when I was actually moving towards work).
Here is the link to Edward Feser’s response to this post, in case someone comes by here later and does not understand the new comments since April 23
http://edwardfeser.blogspot.com/2019/04/aristotelians-ought-to-be-presentists.html
Yes, motion should be seen as potentiality that is being actualized. This would be the sort of property that static object lacks and moving object has( I don't quiet get the circularity charge here).
As for Potentiality on Eternalism It just seems wrong to say that such and such is ever actualized or Just exists potentially. Given that all times are always actual its just that some events or substances have particular location within time.
This isn't the case on presentism because it makes sense to say that before actualization something just existed potentially.
Again maybe I am missing some part of Eternalist picture, though I have seen arguments in literature that Contemporary metaphysics of Powers is incompatible with Eternalism, I guess talk of Act/Potency is very similar to that in this regard too.
It would be news to me that the metaphysics of powers is incompatible with eternalism: I've accepted both for twenty years.
I see nothing particularly problematic about the thought that at t1, x has the property of having a potential for being F in the future, and at t2, x has the property of being F as an actualization of the earlier potential. It is correct that on eternalism it is eternally true that x at t2 has F. But on presentisms compatible with classical theism (i.e., ones without an metaphysically open future), it has always been and will always be true that at t2, x *will* have the property of being F as an actualization of a potential at t1.
Unless you can show that the existence of a potentiality for F is logically incompatible with there existing a realization of F, I don't see the problem.
And Aristotelian presentists tend to accept the possibility of simultaneous causation. But in simultaneous causation, the potentiality has to be simultaneous with the actualization. Thus at the time of the causation, there is both potentiality and actualization, and so an Aristotelian presentist who accepts simultaneous causation has to accept that the existence of a potentiality is compatible with the existence of its realization.
Very nice points, In particular I hadn't actually considered the case of simultaneous causation before. I guess I need to think about this more, here are some thoughts for now.
It seems there is a difference if something is always true and something being always actual the second case seems uniquely problematic.
Simultaneous causation is an interesting case, right now I don't know what to think. Maybe you are right that Power Presentists who accept this should also think Eternalism more favorably but maybe this could also be taken to mean that simultaneous causation is not possible.
Though Here is a difference which presentism would make. On presentism it is still the case that thing being actualized is not fully actual so to say, it is being actualized at every new time.
You might be interested in these papers I will link to.
overall, well I guess a lot depends on what one takes powers view to be, how they are to be characterized and what work they do in ones metaphysics. Here are some publications arguing that Powers ontology or Its account of Laws are incompatible with Eternalism, though it is also argued that they have some problems on presentism too.
https://www.tandfonline.com/doi/full/10.1080/0020174X.2018.1470569
https://philpapers.org/rec/FRIMOL
And Here in a brief section( section 2) it is argued that Powers view can't be used to ground modality given Eternalism.
https://www.academia.edu/29444714/Powers_presentism
Dr. Pruss, could you elaborate on your response to objection 1?
@Alexander R Pruss
“On the at-at theory with continuous time, change is grounded in a sequence of instantaneous states. An instantaneous state is not static. Static things endure over a period of time.
That said, I don't accept the at-at theory any more “
By “instantaneous” I presume you mean t=0.
Indeed, how can there be a continuous succession of adjacent points of 0 dimension?
Any distance away from being co-located would entail the points not touching, as it were.
Thus it seems to me that the notion of a moving object occupying a point of 0 dimension for 0 time is a stepwise human analytical device, whereas the real motion of a real object is logically prior to our stepwise point by point analysis of such motion.
“How is the moving body distinguished from a body at rest given presentism? There are two main options. Either (a) there is a primitive property of being in motion or (b) the moving body is in a location where it didn't use to be. But option (a) is something the eternalist can adopt just well. And option (b) is just a tensed formulation of the at-at theory.”
Yes, if the present moment, rather than being t=0 is instead t=t2-t1 then the present moment is vague because it is trivial to show a smaller value for t given any particular value for t.
Therefore, real objects simply are in motion continuously irrespective of our attempts to apply some sort of instantaneous analysis.
The at-at representation then is actually a delta t, which is realistic in the aggregate, but does not apply to the problem of moment to moment motion or causation.
“Thus at the time of the causation, there is both potentiality and actualization, and so an Aristotelian presentist who accepts simultaneous causation has to accept that the existence of a potentiality is compatible with the existence of its realization.”
Indeed, and thus A-T plants the seeds or its own demise, logically.
Simultaneous causation is the observed fact of material. On a large scale we see gravitation acts in mutually causal processes (though not strictly simultaneous between massive bodies due to propagation delays of causal influences, but locally simultaneous)
Mutual causality is the observed fact at the molecular level and below, as entities interact with each other with no net losses in a perpetual motion system of multibody mutual causality.
“However, the eternalist can just as much say that at time t0 there is a potentiality for movement which is actualized at time t1.”
The analysis of motion was solved mathematically when calculus was reformulated with the limit as its foundation.
The notion of dt could never have been t=0 as t=0 would yield only 0 results. Nor could dt be t2-t1, because that is delta t and does not represent a continuous function, only a staircase approximation.
“The present” then, mathematically is that dt is the limit as delta t goes to 0. With this grounding for the “the present” we can soundly analyze continuous functions, such as motion and mutual causation
"And Aristotelian presentists tend to accept the possibility of simultaneous causation. But in simultaneous causation, the potentiality has to be simultaneous with the actualization. Thus at the time of the causation, there is both potentiality and actualization"
If causation is the link between cause and effect which is formed when the effect is being actualized, then that moment of change is not a time, since instants are not times (times have extension, but instants cannot be said to have extension). And yes, every limited actuality is the actualization of a potency, so what exists is a potency which is actualized, in that the disposition which is actualized is still a disposition, but it is an actualized disposition.
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