There are lots of distinctions between perdurantism and endurantism (or better, between different perdurantisms and endurantisms). Here I want to talk about the following perdurantist claim:
1) Some things (that are not events) have temporal parts.
This does not imply that ordinary things like buildings and persons have temporal parts. And even if one believes the latter, it is still perfectly coherent to reject any account of intrinsic change in terms of temporal parts, or reject an account of personal identity in terms of (properties of) temporal parts, or reject an account of persistence in terms of temporal parts, or reject whatever else temporal parts are used to account for. It is also okay to accept only some of these accounts and reject others. (I for example am a perdurantist who rejects the account of persistence in terms of temporal parts: not only can I say what it is to persist through time without mentioning temporal parts, I even believe that it is possible for a thing to exist through time without having temporal parts.) That's how we get so many perdurantisms and endurantisms. (I think it would be very helpful if people discussing this matter exactly said what they say on each of these issues rather than vaguely asserting that, e.g., things are 'wholly present at different times'.)
What do types, sets, universals, increases, theorems, species and governments have in common that distinguishes them from sticks, stones, mountains, molecules and cities? It's not that only the latter are causally efficacious: on many accounts (e.g. those of Lewis and Kim), events -- the paradigm examples of causal efficacy -- are sets; and why shouldn't one say that if a thing's being charged produces an effect, Charge (the universal) is just as much responsible for this as the thing itself? It's also not that only the latter are located in space or time: impure sets, species, Aristotelian universals and governments arguably are spatiotemporally located as well. And by the Helen Cartwright Theorem Theorem, theorems are sometimes written on blackboards. Indeed, I'm not sure whether anything at all clearly fails to be located in time, unless we require that something located in time must undergo intrinsic change or have a beginning or an end, which sounds ad hoc. Without such restrictions, I can't see a reason to deny that e.g. numbers exist at every time. (Oddly, I'm less inclined to say that numbers exist everywhere. But I might get used to it.)
Entering the philosophy library of Humboldt University got rather unpleasant two weeks ago when a couple of students decided to occupy the building as a kind of protest against planned cuts and tuition fees and capitalism and whatever. I partly support their aims (though I think cuts in the philosophy department would be quite appropriate, given its quality, and I certainly don't want any more 'democratization' of the university), but I don't see how occupying the buildings and keeping me away from doing philosophy is a good way to achieve these aims. Anyway, I'm now in Bielefeld where there are no strikes. I'll probably return to Berlin on Saturday.
Brute necessity is hard to accept, much harder than brute possibility. If someone claims that necessarily there are no purple cows, I expect an explanation. Perhaps he knows what kind of DNA is essential for cowhood and also that this kind of DNA can never produce purple beings, and he also believes that the laws of nature are necessary. This would make his claim understandable. But suppose he had no such explanation. Suppose in fact that we all know that only a minor mutation would be required to produce purple cows, a mutation perfectly compossible with the laws of nature. And still he claims that there could not be any purple cows. This would seem bizarre.
According to the epistemic account of vagueness, there aren't really any vague statements: When we're uncertain whether to call somebody bald that's not because he is a borderline case of baldness. There are no borderline cases. The border between being bald and not being bald is perfectly precise. It's only that we don't quite know were it runs.
Not many people believe in this account. That's surprising, because many people do believe that there are rigid designators -- terms denoting the same thing in every possible world --, and this seems to imply something that looks to me just like (an application of) the epistemic account of vagueness.
Everything is identical to itself, and nothing is identical to
anything except itself. No two things are ever identical. If A and B
are identical then "they" are one, not two.
These are platitudes about identity, or rather about a
somewhat technical use of "identity" common in mathematics and
philosophy.
No doubt there are other uses. For instance, "identity" and its
cognates are often used to express sameness of kind, as in "this
record is the same Jones bought last week". Sometimes, "identity" is
used as a singular term for a thing's characteristc properties or
individual essence, as in "the festival has lost its identity". The conceptual platitudes
above do not apply to these other uses.
Humeans distinguish between how things are in themselves and how they are related to other things. The latter, they say, is always a contingent matter: Even though this cup of tea is about 20m away from a book and stands on a table, it could very well not be 20m away from the book and not stand on the table. In slogan form, there are no necessary connections between distinct entities.
Understood literally, this leads to a position one might call strong humeanism:
Meinongians say that some things do not exist. In other words, existence is a property that befalls only some of the things there are. It follows that by 'existence' these Meinongians do not mean the trivial property that every thing whatever has. What else do they mean? Maybe they mean by 'existence' being in space or time, as Meinong sometimes does. Or maybe they mean an alleged primitive property of certain things. At any rate, I have no objection to this except that I'd rather not use the word 'existence' for that. But I can't really say that ordinary usage is on my side, given that a) ordinary quantification is almost always restricted (though not always in the same way), and b) there is hardly an ordinary usage of 'existence' at all. So far, Meinongianism is utterly trivial. It merely holds that some objects lack a certain property.
Yesterday, I said that it doesn't really matter whether we regard identity simpliciter as identity-at-our world -- individuationg referents extensionally -- or as identity-at-every-world -- individuating referents intensionally. Suppose we want to do the latter, so that the referent of "the amazon" determines a function from worlds to world-bound individuals, that is, an intension. So on the present account, we identify the amazon with something that completely determines the intension of "the amazon". The intension? What if, as two-dimensionalists argue, "the amazon" has two intensions? Which one is the one we want extensions to determine?
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