There is good Aristotelian reason to think that when a particle accretes to a substance--say, when I eat it--the particle ceases to exist. For prior to being accreted, it seems the particle is an independent substance. But a substance can't have substances as parts. And it seems absurd to think that the particle would change from being a substance to a non-substance.
But the view that post-accretion the object that is now a part of the substance is distinct from the object that was accreted is counterintuitive. Here I want to run a partners in crime response to this by showing how a very different and yet fairly mainstream set of assumptions leads to the same counterintuitive conclusion. This should help make that conclusion a little less counterintuitive.
To that end, assume reality is four-dimensional, that objects have lots of temporal parts and that parthood is transitive. This is a fairly commonly accepted set of assumptions. Now suppose I ate a particle x. I will argue that the particle perished in the process. For suppose that x is still a part of me. Let u be a temporal part of x prior to the accretion. Then x is a part of me. But u is a part of x. So by transitivity of parthood, u is a part of me. But that's absurd. So we must deny that x is a part of me on this set of assumptions, too. Hence, this set of assumptions leads to the same conclusion that it is impossible for an object to exist as not a part of something and then continue to exist as a part of that object.
This is a weak argument. If something becomes a part of something else, and objects have temporal parts, then it is only a temporal part which becomes a part, not the whole.
ReplyDeleteRight: And hence the particle itself does not persist as part of the substance, just as on the Aristotelian story.
ReplyDeleteThere is a difference between the two stories, too. On the 4D-temporal-parts story, the particle continues to survive, but not as a part of the substance it is accreted to, while on the Aristotelian story it perishes. I don't know which is more or less counterintuitive.
You are equivocating on “part” again! :-) Integral parthood isn't transitive with temporal parthood. So x is an integral part of you, and u is a temporal part of x, but nothing follows from this.
ReplyDeleteOn a four-dimensionalist picture, there is no significant difference: both are just four-dimensional chunks (typically--though a really thin slice might be three-dimensional) of a four dimensional object.
ReplyDeleteIf you go that route and deny the distinction, then I would be inclined, as I think most would, to deny that x is part of you, since there are 4D chunks of x that aren't part of you. So you either equivocate to get the transitivity going, or else the intuitive support for x being a part of you dissolves. The intuitive support for x being a part you came from treating x as a 3D object totally present now. If you give that up to amalgamate integral and temporal parts, the intuitive support for your premise goes with it, no?
ReplyDeleteChristopher:
ReplyDeleteBut then our 4Der ends up agreeing with the Aristotelian that it never happens that a particle exists first as not a part of a substance and then as part of that substance.
I'm confused about the use of time-unspecified statements in the 4D case.
ReplyDeleteIf I am the 4Der, and I say "there is rain outside," can this be considered true from the 4D perspective if it rained outside last week, even if it has not rained today?
Well, in ordinary contexts statements are relativized to some interval of times containing the statement. Thus, "There is rain outside" can be read as: "Let T be a relevantly small interval of times containing this sentence. The manifold contains rain outside within T."
ReplyDeleteBut in more philosophical contexts, such relativization is gone.
Truth accretes everything, absolutely and equally. =
ReplyDelete