The problem of change/temporary intrinsics
- Last week we discussed a simple puzzle about change, i.e. about persistence, i.e. about having different properties at different times.
- Relations are no problem. I can be intrinsically exactly the same yesterday as I am now and still change wrt my extrinsic properties. Today I'm such that it's raining in Scotland and yesterday I wasn't, even if I undergo no intrinsic change.
- How can I have a certain mass one day and different one another given that mass is intrinsic? I can't have both masses at the same time.
- The solution is to say that I have one mass at one time and another at the other time. But how do we make sense of this? E.g. we don't want to say that having mass is a relation to time, for we thought it intrinsic!
- Endurantism is the commonsense view that things persist in virtually of being wholly present at the times at which they exist.
- I'm all here right now, and when I existed yesterday, I was all there too!
- How does the view fair wrt the problem of temporary intrinsics? Well it seems it has to say that properties are had relative to times. But how?
- Intuitively intrinsic properties like having a certain mass m are extrinsic relations to times. I stand in the having-mass-m relation to some times but not others.
- Intrinsic properties are still intrinsic but having itself is time-relative. I have-at-t mass m but I don't have-at-u mass m.
is the counterintuitive, but scientifically acceptable, view that things persist in virtue of being sums of momentary temporal parts. (This will be qualified later.)
From Brian Greene's The Fabric of the Cosmos
Temporalism vs eternalism
- Temporalism is the view that propositions may change their truth-values over time. The proposition that I am sitting was true and is now false.
- Eternalism is the view that propositions never change their truth values. An utterance of 'I am sitting' at a time t expresses the eternalist proposition "At t, I am sitting". So the expression of a proposition comes with an implicit reference to a time, namely, the time of utterance (if there's no explicit reference to time).
Temporalism vs eternalism
- One reason for believing in temporalism is that temporal operators seem to matter. That I am sitting is intuitively false, yet that I was sitting seems true. So the operator "It was the case that" seems to make a difference.
- One reason for believing in eternalism concerns propositional attitudes like belief. When I was sitting you believed "Michael is sitting". But now that I am standing, do you still believe the false "Michael is sitting"? It seems you believed the same thing then that you do now, namely, "Michael is sitting at time t" for some time t.