Wednesday, January 20, 2010

Quick note on reasons and facts

Against the view that reasons can be propositions and needn't be true propositions, it seems to me that such a view faces a difficulty similar to the difficulty faced by views that identify pieces of evidence with propositions and drops the truth requirement. Suppose there's a reason to drink the stuff in the glass and that reason is that there is gin in the glass. Suppose there's no reason (available) to not drink the gin in the glass and so we say:

(1) You ought to drink the contents of the glass.

If pressed for an explanation, wouldn't this be a true explanatory statement:

(2) You ought to drink the contents of the glass because there is gin in the glass.

But, doesn't (2) entail:

(3) You ought to drink the contents of the glass and there is gin in the glass.

But, (3) is false. There's no gin in the glass.

In general, it seems that one of the things that normative reasons can do is provide part of an explanation as to why certain things ought to be done or oughtn't be done. But, explanatory statements like (2) are factive. So, the only way I see to save the view that severs the connection between reasons and truth is to say that the question as to whether some normative reason is a true proposition or false one depends upon whether it enters into explanatory relations or not. Sort of a weird view, don't you think?

Myself, I don't have the semantic intuitions that let me say things like:

(4) Among the reasons there were to drink the contents of that glass was that there was gin in it, but of course there was no gin in it.

Some have them. Alright, but doesn't everyone pretty much take it for granted that 'p because q' is true only if p is true and q is true?

4 comments:

Mike Almeida said...

Alright, but doesn't everyone pretty much take it for granted that 'p because q' is true only if p is true and q is true?

Suppose a mathematician works out a lengthy proof the conclusion of which is 2+2 =5. The result causes his death. Don't we say that what caused him to die was that, when he was done with the proof, 2+2 equalled 5?

Suppose that after years of psychotherapy, Smith reaches the conclusion that she is a male in a female body, and she decides to have an operation. Why did she have the operation? Because her therapy revealed that she was a male.

Now, when the mathematician is done with the proof, it was not true that 2+2 equalled 5, and when Smith was done with therapy, it was not revealed to her that she was male. Can't reveal to her that p, if not p.

But it does seem right to say that what explained the death of the mathematician was that, when he completed the proof, 2+2 equalled 5. And what explains Smith's going for the operation was that it was revealed to her that she was male.

clifton said...

Alright, but doesn't everyone pretty much take it for granted that 'p because q' is true only if p is true and q is true?

I'm coming a bit late to this discussion, but this seems quite an odd statement.

Where I live there's just been an ice storm that makes driving quite dangerous. Let p(t) = "It is dangerous to drive at moment t." Let q(t) = "It's Thursday at moment t". p(t) and q(t) are currently true, yet I would disagree that everyone takes it for granted that "It is dangerous to drive because it is Thursday" is a true statement.

I've always thought that "p because q" was shorthand for "(1) for all instances t, q(t) implies p(t), (2) q(t) for the current t, and (3) let me helpfully apply a couple rules of inference for you: p(t)".

Is there some situation where this interpretation of "p because q" doesn't make sense?

Clayton said...

Hey Clifton,

I need to double check, but I said:

'p because q' entails 'p & q'.

I deny:

'p & q' entails 'p because q'.

Mike,
I love the examples, but I have some sympathy for those who say that what caused him to die the derived result was that 2+2=5, he seemed to have shown that 2+2=5, or something like that (i.e., a description of an action, event, or state of mind that does not entail 2+2=5). That's not very deep and it doesn't explain why they need to be redescribed, but that's my initial reaction.

clifton said...

Oh, I'm sorry. Somehow I read "if and only if", and continued to believe you had written "if and only if" even as I cut and pasted the sentence into my comment.