Tuesday, February 9, 2010

Reasons and entailment

They've posted the program for the 2010 Epistemic Conference. If you want to read some massive abstracts, that's the place to go.

On the drive home last night, I was thinking about reasons for action and belief (after thinking murderous thoughts about that a*&\$&\$# in the white Hummer weaving through traffic). It seems quite plausible that a reason to believe p counts as a reason to believe q if you know q is a consequence of p. I was trying to think if there were similar principles for action, and it seemed like it was a bit harder to formulate the right principle.

What if we said this?

(1) If R is a reason for S to X and that S X's entails that S Y's, R is a reason for S to Y.

Suppose there's a reason for me to shake your hand. That I shake your hand in the normal way entails that I have not had my arm removed. (If my arm and hand were detached, I shouldn't hold it in my left hand and extend it to you.) I don't think it's obvious that the reason I have to shake your hand is a reason to keep my arm attached to my body. So, I don't know if reasons to A are, invariably, reasons to refrain from performing an action that would prevent one from A-ing. If I didn't have an arm, I wouldn't have a reason to shake your hand at all. Sure, don't chop the arm to avoid shaking a hand, but I don't think that requires (1) for its proper explanation.

Suppose there's reason for me to apologize sincerely for what I did. I cannot do that unless I did the thing I'm to apologize for. I don't think reasons to make amends give me reason to do the thing I'm to apologize for. That contains a backwards looking set up, but I think we can cause trouble for cases where the relevant acts are all future acts. If there's reason to A and not to A but the reasons to A win out, I'll acquire a reason to explain my actions to those who were ill served by my decision to A rather than do something else, such as B. I don't think that the reasons I'll have to explain myself for A-ing rather than B-ing are reasons to A (they count in favor of B-ing), but I can't offer this sort of explanation to those ill-served by my A-ing unless I do in fact A. So, another case where we have reason to do something (i.e., A-ing) that necessitates the doing of something else (i.e., not B-ing) where the reasons that are reasons for an action (explaining to those ill-served by my A-ing) that are not reasons for an action (A-ing) I'll perform if I perform an action that necessitates it (explaining why I A'd in spite of the fact that it left some ill-served).

Are there better ways of writing out a kind of closure principle for reasons for action? If we switched from things done to things brought about, that would make our principle for reasons for action closer to our principle for reasons for belief, but I think this principle is susceptible to counterexamples as well. A reason to bring about the state of affairs in which I catch a criminal in the act is not a reason to bring about the state of affairs in which there's a criminal to catch, a reason to bring about a state of affairs that would bring about a state of affairs that I should make reparations for is not a reason to bring about _that_ state of affairs. (Or, is that not right?)