No new reading for Tuesday.

1. No new reading for Tuesday. Next Thursday’s reading response should address Georges Rey’s “Resisting Normativism in Psychology” (Chapter 5)

2. The McKinsey Problem 1. I can know a priori the contents of my beliefs, for example, my belief that water is wet. 2. My thinking that water is wet conceptually implies that H2O exists. (This is entailed by externalism, so long as we take for granted what we think we know now about chemistry.) 3. That H2O exists can be known only a posteriori.

3. What’s the problem? If I know that I’m thinking that water is wet, and I know a priori that externalism is true, then I should be able to know a priori that H2O exists (whether one appeals to CAK or CA). This contradicts (3). At least one of the 3 claims must be rejected.

4. Brueckner’s Solution Externalism does not entail that (2) can be known a priori; even if we can know a priori that externalism is true, this does not yield a priori knowledge of the specific external conditions necessary for us to have thoughts with the relevant contents. It’s merely metaphysically necessary that H2O exists if I’m thinking that water is wet (AND if water is, in fact, H2O); it’s not conceptually entailed by my being in that state alone, even if we know externalism a priori.

5. A Posteriori Necessity Semantic externalists are widely taken to have shown that some necessary truths are (or can be, relative to our powers?) known only a posteriori. “Water is H2O” is necessarily true, because it expresses the same proposition as “H2O is H2O,” which couldn’t possibly be false. But we had to do empirical work to figure out that the stuff we were talking about is H2O.

6. CAK and CA (p. 42) CAK requires that you know the relevant conditional a priori, in order to derive the thereby a priori known consequent from the a priori known antecedent. CA requires only that a logical deduction can get you from the a priori known antecedent to the consequent (which is thereby known a priori).

7. The gap between CAK and CA is important because we might be thinking about metaphysical necessity that can’t be known a priori. Think about the difference between ‘Larry’ and ‘Pegasus’ or between ‘water’ and ‘phlogiston’.

8. What can a semantic externalist known a priori, with regard to (2)? If E can be known a priori, it would be something like “if I’m thinking that water is wet, then if ‘water’ refers then the stuff it refers to exists”

9. Basic Concepts Alternative response to the McKinsey problem: some of our concepts – the basic ones – are such that merely having them guarantees that they refer to something in the world. If so, then if we know which ones these are, then knowing the content of our own mental states that involve these concepts might well give us a priori knowledge of the world, making (3) false, but acceptably so.

10. Empty Concepts But only if we know a priori which of our concepts are basic. Even if we know which concepts are basic, the set of basic concepts might not include some of the concepts involved in mental states to the content of which we think we have introspective access – ‘water’, for example.

11. According to Brueckner, this provides one more reason for thinking that there is no statement E comprised of a conditional one can know a priori (by being conceptually derived from anti-individualism). At the same time, however, Brueckner’s reasoning might simply give the externalist reason to reject (1) (instead of focusing so much on (2)).