Wolfgang Schwarz

Solution

Here comes the solution to this year's Christmas puzzle:

First, is the story in the museum true or false? The crucial question is whether the last sentence in it is true. It goes:

The Museum of the Myth (Another Christmas Puzzle)

The Museum of the Myth is not very comprehensive. In fact, it only contains a single story:

The Museum of the Myth is not very comprehensive. In fact, it only contains a single story. The story is not particularly exciting. Moreover, some people wonder whether it is actually false. If not, it would of course be incorrectly classified as a myth. So one day, the oracle is asked about the story. Luckily, the oracle is quite reliable: if the story is true, it undoubtedly finds out that it is.

The story is not particularly exciting. Moreover, some people wonder whether it is actually false. If not, it would of course be incorrectly classified as a myth. So one day, the oracle is asked about the story. Does it find out whether it is true?

Haecceitism, Materialism, Zombies, and Counterparts

If haecceitism is true, materialism is false. For if haecceitism is true, there is a world w just like ours except that you and I have traded places. By that I don't mean that in w someone with my origin or my DNA or my soul leads a life quite like yours. No, haecceitism holds that it is possible for us to trade places completely, so that in w not only my life is just like your actual life, but also my origin, DNA and soul are just like your actual origin, DNA and soul. w and our world do not differ in any qualitative respect at all. They differ only in facts that essentially involve you or me, such as the fact that in w it's you who is writing this posting. Whatever 'physical' means, it is clear that the physical facts are not of this kind. That's why materialism is false if haecceitism is true: Materialism demands that there is no difference at all between our world and any minimal physical duplicate of it.

Extreme Haecceitism

Geoff at Too Much Text points out that the implausible hyper-essentialism implied by Kripke's account of rigidity can be avoided by adopting radical anti-essentialism, the view that there are no non-trivial (qualitative) essential properties at all. On this view, even though there is a precise boundary between a thing's essential and non-essential properties, the boundary is not very mysterious because it classifies virtually all properties as non-essential.

Two Kinds of Rigidity

I want to write something about rigidity in the philosophy of mind. But first I have to say more about rigidity. (Apologies in advance: this is all going to be rather basic. But I'll need it, and I found that many people disagree with it.)

Extended Atoms

In my last post, I said that I do not believe that every extended thing must have parts. Sam disgrees, arguing that whenever something is extended over length h, we can restrict our attention to a part of it with length h/n for any n < h.

Temporal Parts and Restrictions on Fusions

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:

Abstract and Concrete

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.)

Unhelpful Trees

Today I wondered about the connection between

Under certain ideal conditions, something is conceivable iff it is possible

and

Something is possible iff it is conceivable under certain ideal conditions.

So I asked my tree prover whether

Strike Asylum

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.

Modal Epistemology

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.