G. E. Moore famously responded to the hedonist's claim that the only goods are pleasures by asking, in effect: But is pleasure good? The point, I take it, is that the sense of 'good' allows us reasonably to resist the identification of goodness and pleasure. For it remains an open question whether pleasure really is good. To appreciate the contrast between open and closed questions, consider Tom the bachelor. Given that Tom is a bachelor, it is not an open question whether Tom is an unmarried adult male. This is because the sense of 'bachelor' does not allow us reasonably to resist the identification of bachelors with adult unmarried males. It is built into the very sense of 'bachelor' that a bachelor is an adult unmarried male. But it is not built into the very sense of 'good' that the good is pleasure.
It occurred to me while cavorting in the swimming pool the other morning that a similar Open Question gambit can be deployed against the thin theorist.
Suppose a thin theorist maintains the following. To say that Quine exists is to say that Quine is identical to something. No doubt, but does the something exist? The question remains open. Just as 'good' does not mean 'pleasurable,' 'something' does not mean 'something that exists.' Otherwise, 'Something that does not exist' would be a contradiction in terms. But it is not. Consider
1. A matter transmitter is something that does not exist.
It follows from (1) that
2. Something does not exist.
I am not claiming that (2) is true. I hold that everything exists! My claim is that (2) is neither a formal-logical contradiction, nor is it semantically contradictory, i.e., contradictory in virtue of the senses of the constituent terms. Here is an example of a formal-logical contradiction:
3. Something that does not exist exists.
Here is an example of a sentence that, while not self-contradictory by the lights of formal logic, is semantically contradictory:
4. There are bachelors that are not unmarried adult males.
'Some cat is fat' and 'A fat cat exists' are logically equivalent. But do they have exactly the same meaning (sense)? This is an open question. And precisely because it is an open question, the two sentencces do not have the same meaning, pace London Ed, van Inwagen and the rest of the thin boys. For there is nothing in the very sense of 'Some cat is fat' to require that a fact cat exist. Compare 'Some unicorn is angry.' Does that require by its very sense that an angry unicorn exists?
Am I getting close to the point where I can justifiably diagnose van Inwagen and the boys with that dreaded cognitive aberration, existence-blindness? Or is it rather the case that I suffer from double-vision?