I found that Sally Haslanger’s excellent comments at the APA Eastern were largely (but not entirely) drawn from her forthcoming paper Persistence Through Time. There’s lots to talk about in this paper, so lets take it one step at a time.

Why is the problem of temporary intrinsics a problem? Here are three possible answers.

First, we might have a brute ‘metaphysical intuition’ (as Ted puts it) that shapes are intrinsic, not relational. But this looks like a hopeless line. Sure shapes simpliciter are intrinsic. What aren’t intrinsics are shapes-of-the-cross-section-determined-by-T, where T is some external object. (E.g. the hyper-plane of space-time points simultaneous with me according to my reference frame.) But the allegedly intrinsic properties that generate the problem of temporary intrinsics are not shapes simpliciter but shapes of cross-sections with the hyper-plane of simultaneous points etc. So this is no good. This is just obviously relational, and hence it is reasonable to assume it is extrinsic.

Second, we might worry that with no temporary intrinsics we’ll be left with bare particulars, and they’re bad. As Haslanger points out (on page 16), this won’t do either, because we’ll still have permanent intrinsics to clothe our particulars. That seems right to me.

Third, we might worry that no temporary intrinsics means no change. Haslanger seems prepared to temporarily concede this for the sake of the argument, but I don’t think she need even have done that. It’s pretty clear (as I’ve argued before) that we can have real change without change in intrinsic properties.

I’m tempted to conclude that there’s no metaphysical problem of temporary intrinsics. I still think that what Ted calls ‘semantic’ intuitions about intrinsicness could be important for settling semantic disputes between four-dimensionalists. But I don’t think we can use this club to bash three-dimensionalists with.