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9. Objects / E. Objects over Time / 3. Three-Dimensionalism

[objects extend in space, but not in time]

12 ideas
'Dense' time raises doubts about continuous objects, so they need 'continuous' time [Harré/Madden]
     Full Idea: Since discontinuities in a dense set of temporal points lead to doubts about the existential integrity of a thing, the thing-ontology demands that a dense time be continuous.
     From: Harré,R./Madden,E.H. (Causal Powers [1975], 6.IV)
     A reaction: This seems to be a rather unequivocal assertion about a rather uncertain topic. If quanta can move in 'leaps', which appear to abolish the notion of what happens 'between' two states, who can say what objects might manage to do?
Endurance is the wrong account, because things change intrinsic properties like shape [Lewis]
     Full Idea: The principal and decisive objection to endurance, as an account of the persistence of ordinary things, is the problem of temporary intrinsics. Persisting things change their intrinsic properties, such as their shape. My own shape keeps changing.
     From: David Lewis (On the Plurality of Worlds [1986], 4.2)
     A reaction: Presumably if something was going to endure through time it would need a shape. If it has no particular shape, it lacks identity? Lewis discusses the problem at length. Why is a precise shape essential to anything?
There are three responses to the problem that intrinsic shapes do not endure [Lewis]
     Full Idea: The problem for the endurance view of temporary intrinsic properties like shape is met be either saying shape is a disguised relational property, or only present properties are intrinsic, or the shapes belong to different things (perdurance).
     From: David Lewis (On the Plurality of Worlds [1986], 4.2)
     A reaction: [compressed] It is certainly implausible to deny that shape is a feature of all physical objects. Or it appears to be. Shapes are hard to pin down at the quantum level. How do you sharply divide moments for the perdurance view? ...
3-D says things are stretched in space but not in time, and entire at a time but not at a location [Fine,K]
     Full Idea: Three-dimensionalist think a thing is somehow 'stretched out' through its location at a given time though not through the period during which it exists, and it is present in its entirety at a moment when it exists though not at a position of its location.
     From: Kit Fine (In Defence of Three-Dimensionalism [2006], p.1)
     A reaction: This definition is designed to set up Fine's defence of the 3-D view, by showing that various dubious asymmetries show up if you do not respect the distinctions offered by the 3-D view.
Genuine motion, rather than variation of position, requires the 'entire presence' of the object [Fine,K]
     Full Idea: In order to have genuine motion, rather than mere variation in position, it is necessary that the object should be 'entirely present' at each moment of the change. Thus without entire presence, or existence, genuine motion will not be possible.
     From: Kit Fine (In Defence of Three-Dimensionalism [2006], p.6)
     A reaction: See Idea 4786 for a rival view of motion. Of course, who says we have to have Kit Fine's 'genuine' motion, if some sort of ersatz motion still gets you to work in the morning?
An object 'endures' if it is always wholly present, and 'perdures' if different parts exist at different times [Lowe]
     Full Idea: The 'endurance' view is that an object persists by being 'wholly present' at more than one time, and the 'perdurance' view is that an object has different temporal parts which exist at different times.
     From: E.J. Lowe (The Possibility of Metaphysics [1998], 5)
     A reaction: It is tempting to say that only a philosopher would come up with a view as bizarre as the second one. Trying to imagine God's view of time has led to a lot of confusion. Endurance seems to need substance, so bundle views of objects encourage perdurance.
Three-dimensionalists assert 'enduring', being wholly present at each moment, and deny 'temporal parts' [Sider]
     Full Idea: Three-dimensionalists say that things have no 'temporal parts', that they 'endure', and that they are wholly present at every moment of their careers.
     From: Theodore Sider (Four Dimensionalism [2001], 3)
     A reaction: An obvious problem case for being wholly present would be the building and fitting of a large ship, where it might seem to be present before it was wholly present.
Some might say that its inconsistency with time travel is a reason to favour three-dimensionalism [Sider]
     Full Idea: Some might even regard inconsistency with time travel as an advantage of three-dimensionalism, as a vindication of a prior belief that time travel is impossible! I see no merit in these claims.
     From: Theodore Sider (Four Dimensionalism [2001], 7.2)
     A reaction: I do! Sider cheerfully says that there are good reasons to believe that time travel is possible, and then use this possibility to support his four-dimensional view, but I personally doubt his assumption. The evidence for time travel is flimsy and obscure.
Endurance theory can relate properties to times, or timed instantiations to properties [Hawley]
     Full Idea: Endurance theory might claim a banana stands (atemporally) in different relations to different times (being-green-at to Monday), ..or has different instantiation relations to different properties (instantiates-on-Monday to being green).
     From: Katherine Hawley (How Things Persist [2001], 1.3)
     A reaction: She suggests that the first approach is more plausible for endurantists. I think she is right (assuming these are the only two options). Monday awaits a banana, but yellow doesn't.
Endurance is a sophisticated theory, covering properties, instantiation and time [Hawley]
     Full Idea: Endurance theory is not just a default 'no-theory' theory, for it must incorporate a sophisticated account of properties and instantiation, and requires a certain view of time if it is even to be formulable.
     From: Katherine Hawley (How Things Persist [2001], 1.8)
     A reaction: A bit odd to claim it is a sophisticated theory when it is held (at least in our culture) by absolutely everyone apart from a few philosophers and physicists. The sophistication may come with trying to describe it using current metaphysical vocabulary.
The persistence of objects seems to be needed if the past is to explain the present [Haslanger]
     Full Idea: The notion that things persist through change is deeply embedded in ideas we have about explanation, and in particular, in the idea that the present is constrained by the past.
     From: Sally Haslanger (Persistence, Change and Explanation [1989], 1)
     A reaction: I take this to be both an important and an attractive idea. Deniers of persistence (4D-ists) will presumably have some ability to explain the present, but it is the idea of the present being 'constrained' by the past which is a challenge.
Persistence makes change and its products intelligible [Haslanger]
     Full Idea: Persistence offers intelligibility: the possibility of understanding a change, and of understanding the products of it.
     From: Sally Haslanger (Persistence, Change and Explanation [1989], 8)
     A reaction: I think this is exactly right, and it is a powerful idea with wide implications for metaphysics. Haslanger claims that an understanding of 'substance' is needed, which leads towards my defence of essentialism.