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Soames on A Priori Knowledge

I'm trying to catch up with Dave Chalmers's reading of Scott Soames's Reference and Description. I'm still at chapter 4, and my reaction to it is not quite the same as Dave's. (I began this entry as a comment over there, but it somehow grew way too long.)

Let's stipulate that "Lee" (rigidly) denotes the youngest spy (if there is one). Soames argues that if

Substitutional Quantifiers

Until recently, I thought that there are no quantifiers in ordinary discourse for which a substitutional interpretation is adequate, or helpful. I still think this is true for almost all cases, including quantification over fictional and intentional objects. But here are two cases where a substitutional interpretation looks ok.

First. The world can be completely described in precise vocabulary. There are no vague objects with irreducibly vague bounderies or heights or colours. Rather, for many terms, like "Mount Everest", it is indeterminate exactly which perfectly precise object they denote. But it is very natural to say that Mount Everest has vague boundaries. Instead of denying it, I'm inclined to offer some kind of reinterpretation, such as: there are different objects slightly differing in their boundaries between which "Mount Everest" is indeterminate; or: for no precise boundaries b is it true that Mount Everest has boundaries b; or: for some precise boundaries b is it indeterminate whether Mount Everest has boundaries b. All these are true, and all of them could be meant by "Mount Everest has vague boundaries".

Basic Expressions

Call an expression E scrutable with respect to a class of expressions C iff it is a priori that all true sentences involving both C and E are a priori deducible from all true sentences involving only C. Equivalently, E is scrutable with respect to C iff there are no worlds w1 and w2 of which exactly one is in the 1-intension of some C+E-sentence, whereas all 1-intensions of C-sentences contain either both worlds or neither.

Is every expression scrutable with respect to some class of expressions to which it does not belong? If the relevant language has synonyms for all expressions, that's trivial. We should better ask about families of expressions: what classes of expressions are scrutable only with respect to expressions containing other members of their class? Call such classes indispensible. Large classes of expressions like the class of all expressions are obviously indespensible, as is probably the class of indexicals and the class of quantifiers. Dave Chalmers would also add the class of phenomenal expressions. As a type-A materialist, I would rather not.

Time-Indexed Relations

I don't share Lewis's strong intuitions that shape properties must be purely intrinsic rather than time-indexed. For me, the argument from intrinsic change works much better with certain relations, in particular mereological relations and identity.

Suppose x is part of y at time t1, but not at t2. Perdurantists can say that the temporal part of x at t1 is a part simpliciter of the temporal part of y at t1. Time-indexers will say that the whole of x stands in the part-at-t1 relation to the whole of y, where this relation is not analysable in terms of non-indexed parthood: time-indexed parthood is all there is. But no! Subsets are parts simpliciter of sets, battles are parts simpliciter of wars, the story of the Trojan War is a part simpliciter of the Illiad, geometry is a part simpliciter of mathematics, XPath is a part simpliciter of XSLT, and so on. These things are not part-at-time-related, but part-related.

Detecting Emptiness

Thought experiments about reference often focus on cases where a term intuitively refers to something other than what a certain theory would predict. This way, we can find sufficient conditions for reference. I think it is just as interesting to consider cases where the term does not refer at all, which gives us necessary conditions.

For example, suppose "hydrogen" and "Aristotle" refer causally, that is, denote whatever stands in a certain causal relation to our use of these expressions. Then what would it take to find out that hydrogen does not exist? We would have to acquire etymological information about the causal-historical origin of the term "hydrogen": only if something went wrong in that causal path could we conclude that there is no hydrogen.

Paper CD Cases

I have a slight cold, so instead of doing philosophy I've rearranged the music collection on my hard drive and written a LaTeX template to print paper CD cases: template.tex. I've also written a little Perl driven web form that generates a ps file from the template and the entered title/tracks: cdcase.pl. Sorry, you can't test it online, as I don't have LaTeX installed on this server. Here is an example output: cdcase.ps.

Emperors and Tree Prover Updates

I've uploaded another revision of the emperors paper. The best thing about this version is that it's four pages shorter than the previous ones.

Unrelatedly, I've removed the Herbrand restriction from my tree prover. The restriction says that a Gamma node should not be expanded more often than there are closed terms on the branch. But currently, the prover doesn't keep track of the number of closed terms, it only keeps track of the number of function symbols (including 0-place function symbols, i.e. individual constants). So if a lot of s(0), s(s(0)), etc. are on a branch (as in this proof, where I noticed the bug), the prover wrongly applied the Herbrand restriction, thinking all of them are only two closed terms.

All my testcases work just as well without the Herbrand restriction. If you find a case where the performance got worse, please let me know. It shouldn't be difficult to fix it (rather than removing it completely).

Members and Gunk

Suppose there are at least proper-class many possibilia. Does it follow that some fusions of possibilia are not members of any set? For the last two years or so I thought it does. My reasoning was that if some of the possibilia correspond one-one with all the sets, then some atoms of possibilia also correspond one-one with all the sets (for there cannot be proper-class many fusions of set-many atoms); but since there are always more fusions of atoms than atoms, it follows that there must be more fusions of atoms of possibilia than sets, and hence that some (in fact, most) of these fusions lack a singleton. This does not take into account atomless possibilia, but I always thought the reasoning would easily carry over, by something like the fact that even with gunk

What is Counterpart Theory?

Well, I know what Counterpart Theory is not: it is not a theory according to which ordinary things do not really exist at other possible worlds.

There are two readings of "ordinary things do not exist at other worlds". The first is a neutral reading on which things exist at another world in the way they sleep at another world or win elections at another world: whatever possible worlds are, they somehow represent things as existing and sleeping and winning. In this sense, something exists at a world iff the world represents it as existing. Anyone who accepts possible worlds talk at all accepts that ordinary things exist at other worlds in this sense.

Donations for Tsunami Victims

My fellow Germans have donated very generously to the tsunami relief effort. That's good. But it's remarkable that we have donated so much to this cause, and far less to other good causes. 100 Euros given to the tsunami victims could also have been spent, say, to help the refugees in Darfur, or to support the reconstruction of war-torn Uganda or Sierra Leone, to provide medical care for people in Ethiopia or Bangladesh, to prevent deforestation, overfishing and soil erosion, to fight climate change, and so on. Donations are urgently needed all the time.

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