I've got three new drafts of metaphysics papers up on my (new) website.
They are:
Balls and All
In this paper I lay out a rather unusual combination of views about spacetime, mereology and material objects. The view is coherent, I claim: and if it is coherent it seems to provide a counterexample to a number of assumptions that are made about what sorts of views have to go together. (In particular I use it to argue against a number of Ted Sider's arguments in his Four-Dimensionalism.)
Disposition Impossible, with C.S. Jenkins
In this paper Carrie and I investigate "unmanifestable dispositions": dispositions to PHI in C, where either PHI is impossible or C is. We argue that objects have such dispositions, and it is a non-trivial matter which ones they have. We also argue that these impossible dispositions play, or can play, significant theoretical roles. If we are right, a number of standard styles of theories of dispositions are in trouble.
The third is a piece of "applied metaphysics", I suppose, at least if work on counterfactuals counts as metaphysics. My impression is that it often is counted that way, even though it is at least as much philosophy of language and philosophy of science:
Why Historians (and Everyone Else) Should Care About Counterfactuals.
I discuss eight good reasons historians can usefully concern themselves with counterfatuals: some have been argued for before by others, but even in these cases I either have different characterisations of exactly why conditionals are important, or have different arguments for their importance in historical method.
Any feedback on any of the three papers would of course be welcome. (Obviously not any feedback. But you know what I mean.)
Hi Daniel, quick question regarding "Balls and All"
ReplyDeleteYou say "If perdurance requires that for every stretch of time that an object exists, it has a temporal part that exists only at that time, then this is a the condition satisfied by a material object O when every (non-null) region-intersection of O and a time is itself a material object. The system so far outlined does not rule this out, but obviously it does not require it either."
I don't think I understand. Here's my problem. We have a four-dimensional pointless topology. Hyperplanes are defined by Cauchy sequences of balls. A time-slice is a certain kind of hyperplane. Given an object O, we intersect O with this time-slice and ask: Is the intersection itself a material object?
Isn't the answer just "No"? A hyperplane is not an open region, and so is not an object in the topology at all. So the intersection of a hyperplane with O---a "timeslice" of O---is not an object in the topology (let alone a material object).
Or am I making unwarranted assumptions about the topology?
Hi Tim: you're right that the intersection of a hyperplane and an object is never a candidate to be a material object, in the system described. In the sense of "intersection" in which one region intersects another iff they share a subregion, of course, hyperplanes don't intersect objects at all: but once we extend the geometry to have points, planes, etc. we can define "intersections" of planes and regions, of course - those intersections will be sets of points, I assume.
ReplyDeleteSo that's all true. My proposal for a "temporal part" isn't the intersection of a hyperplane and a region, though. It's the intersection of a certain region identified as a "time" with the object. "Times" here aren't hyperplanes or even sets of points bounded by hyperplanes - they are regions. I say which regions these are on p 11: the continuous times are those regions bounded by two hyperplanes that are parallel to the time axis and non-zero distance apart, and the times in general are fusions of those continuous times.
Construed that way, the times are regions, and so the intersections of times and physical objects are regions that may, or may not, themselves be material objects. (Of course we won't get minimal temporal parts, or times - but that's okay.)
Please let me know if I've misunderstood what's behind your worry.
No, you understood my worry just fine! Thanks.
ReplyDeleteHowever, this generates a different worry; tell me where I'm going wrong:
(1) Times are open regions of the topological space (premise)
(2) Material objects are open regions of the topological space (premise)
(3) intersecting a time with a material object gives you an an open region (topology)
(4) that region is also a material object, unless it's the empty region.
Then the answer is: Yes, for every stretch of time that an object exists, it has a temporal part that exists only at that time.
Is the problem with (4): we have an object, but perhaps not a *material* object? Certainly that's entailed by your supersubstantivalism.
(This leaves me a bit confused about some of the claims in section 3, especially the "As we saw in the previous section [section 2], the view offered here is supersubstantivalist even though it is not perdurantist about material objects nor about spacetime." But maybe it's best if we discuss (1)-(4) first!)
Yep, the problem is (4). Not all regions are material objects. (I notice that when I set the view up on p 9-10, I am talking about "physical objects". I should make the paper consistent and use one of "physical object" or "material object" throughout.) Only some of them are physical/material objects, though I am officially neutral about whether the "is a material object"/"is a physical object" is unanalysable or gets a further analysis.
ReplyDeleteNote also that only material objects/physical objects stand in part-whole relations, on this proposal: which is why we don't get perdurantism about spacetime dropping out. ("intersection" in our discussion here is a matter of sharing a sub-region, not necessarily anything mereological).
Incidentally, I'm not sure whether I'm committed to the regions being open - the obvious model is with open regions, but I'm not seeing the proof straight away that the set of points associated with one of these regions can't include the limit points. But maybe there's a straightforward proof of this that I'm missing!
You might be wanting to object that we should treat all spatiotemporal regions as material objects or physical objects - if one means "quantified over in best physics" by "physical object" then presumably they would be - which is why I was thinking of changing to "material object", though I see that change wasn't carried through as ruthlessly as I thought.
Ok. Small technical point: I meant "open" in the sense of "is a region of the topology". So I was just relying on the fact that a topological space is closed under arbitrary finite intersection. (In particular, I wasn't considering regions of R^4 that are open under the topology given by its standard basis, which I think is what you raised.)
ReplyDeletePhilosophical question: You have a material/physical object (which I'm still assuming is an open region, i.e. a union of balls). You intersect it with another open region; you get an open region. How could this open region *fail* to be a material object?
I can see some possible answers to this, but I can't see how any of them depend particularly upon approaching the question via a pointless topology. Perhaps you could explain; that bit seemed to go by very quickly in the transition from pp.9--15, but seemed pretty important.
Hi Tim,
ReplyDeleteI am not quite sure what sort of answer you want to the first question. I presume you are asking what philosophical motivation there could be to deny that a sub-region of a region identified with a material object: if it is some other sort of "how possibly" question my apologies.
I do not take a stand on this in the paper, as I recall, but it seems to me that there are a number of potential philosophical motivations with some plausibility. One is a desire to conform to commonsense. As far as I can tell, commonsense is not committed to there being a material object that is exactly co-located with me that came into existence 7 minutes ago and will go out of existence in a minute, and such objects don't seem to be on standard lists of ordinary things: tables, chairs, humans etc. It's controversial whether that is commonsense, and controversial what to do about that, but many endurantists have drawn aid and comfort from that sort of thing in arguing we are not made up of temporal parts.
There are also more abstract kinds of reasons. Tempting candidates for which regions are the material objects and which are not might include counting those regions that instantiate various material-objecty kinds of properties - charge or mass, for example. There's no guarantee that just because a region instantiates some of the relevant properties all of its sub-regions will. Indeed, on some pictures of the world where e.g. physics serves up particles as fundamental as far as the physics is concerned, it might be a tempting metaphysics to allow that the simple material objects are non-point sized simples. Again, there's an argument to be had about whether those sorts of considerations work, but they motivate some people.
That's two lines of approach, though no doubt there are others that have been advanced in the anti-perdurance literature, and some of those might be adaptable for this purpose too.
Many of these don't depend on approaching the question from a pointless topology - that's part of what I meant when I said on pp 12-13 that that sort of detail of the system wasn't important for most of my purposes, and tried to say what I thought was important.
One place (though I suspect not the only place) where it does make some difference is on the issue of whether there is a distinctive form of endurantism here that is philosophically motivated: see pp 24-5. You can, of course, have spanners or neo-spanners in a pointy framework as well, but it seemed to me there was mileage to be had in thinking about the options here when our background theory is "pointless".