Monday, March 16, 2009

You don't gotta do what you don't gotta do

I've been reading "You Gotta Do What You Gotta Do" in the latest edition of Nous (here, but institutional access is required) to see if it's really possible to derive the negation of the Humean theory of motivation from a tautology. It would be cool if it was possible. It would be just as cool if it was possible to derive the theory from a tautology. I'm sceptical.

Let's suppose that you can refute the Humean theory if you can show that there is a rational transition from a set of beliefs to an intention, desire, or attempt. The proposal is that there is such a rational transition, it's the transition in accordance with:
"The Move": B[OΦ] to Φ-ing.

In English, you make (The Move) when you transition from the belief that I ought to Φ to Φ-ing (or, I suppose intending to Φ, trying to Φ, etc...).

Is (The Move) a reasonable move for the mind to make? Gibbons says it is. Forget about (The Move) for a moment and think about (The Umbrella):

"The Umbrella": B[it's raining] to taking an umbrella.

This transition, from belief to action does depend upon what other mental states you're in (e.g., the desire to stay dry or make a friend at the bus stop).

Compare (The Umbrella) to (The Rule):

"The Rule": If it's raining, take an umbrella.

It seems that the transition (The Umbrella) is at least as rationally acceptable as (The Rule) and it seems that the rational acceptability of either depends upon pretty much the same sorts of wants, desires, further intentions, etc...

Little seems to distinguish (The Rule) and (The Umbrella) from (The "Ought"):

"The 'Ought'": If it's raining, you ought to take an umbrella.

To get from (The Umbrella) to (The Rule), you take the content of the belief and write that as the antecedent of the imperative. To get from this to (The "Ought"), we rewrite the consequent as a declarative sentence using "ought".

Important Point. After you construct your imperative and your ought statement, note that the starting point (e.g., (The Move), (The Umbrella) is no less acceptable than your derived ought statement.

If we make these sorts of changes to (The Move), we get:

(Just Do It): If you ought to Φ then Φ.
(Gotta Do): If you ought to Φ you ought to Φ.

Gibbons writes:
If (The Move) is at least as acceptable as (Just Do It), which is at least as acceptable as (Gotta Do), then (The Move) is looking pretty good. If (Gotta Do) is, as it appears to be, a tautology, then its acceptability cannot depend on your desires. If p is a tautology, you ought to believe p whether you want to be reasonable or not, at least when the question comes up. Since the question of (Gotta Do) has come up, you are rationally required to accept it. So you're rationally required to accept (Just Do It). So (The Move) has the same rational status as the transition from the beliefs that p and that if p then q t the belief that q. If the input to the transition is no good, the output may be just as bad. But if (Gotta Do) is a tautology, the transition itself is unimpeachable.

Here's a worry. Suppose someone doesn't make (The Move). It seems that there's something wrong with them. The Humean shouldn't deny that there's something wrong with someone who doesn't make (The Move). Does that mean that the subject has violated (Gotta Do) or (Just Do It)? No, not unless there's an entailment from B[OΦ] to Φ. There's no such entailment. Neither the Humean nor Gibbons thinks otherwise.

So, what does it mean to say that (The Move) is at least as acceptable as (Gotta Do)? It can't be that anyone who fails to make (The Move) has violated (Gotta Do). It has to be that from the perspective of the agent, if she fails to make (The Move) she has failed to conform to (Gotta Do). The transition from believing you ought to Φ to Φ-ing is no more problematic from the subject's perspective than accepting what you take to be a tautology. Fine. But isn't the Humean response simply this? Just as you shouldn't both believe p to be a tautology and fail to believe p, it doesn't follow from the fact that you believe p to be a tautology that you should believe p. That depends, inter alia, upon the status of your belief about p's status as a tautology. If you shouldn't believe p to be a tautology, even if you believe this it doesn't follow that you should believe p. Similarly, just as you shouldn't both believe you ought to Φ and fail to Φ, it doesn't follow from the fact that you believe you ought to Φ that you ought to Φ or that it would be the slightest bit rational to Φ. That depends upon whether you should believe you ought to Φ in the first place. Nothing said thus far shows that it can be reasonable, permissible, or justified to believe you ought to Φ without some sort of desire that Φ-ing would serve and so we haven't seen how (The Move) could be a rational one for the mind to make without any desires at all.

Putting the point slightly differently, we can see that the argument above is too good to be true. If (The Move) is at least as acceptable as (Just Do It), which is at least as acceptable as (Gotta Do), then (The Move) is looking pretty good. If (Gotta Do) is, as it appears to be, a tautology, then its acceptability cannot depend upon your further beliefs that you most certainly shouldn't Ψ and that you can't Φ without Ψ-ing. Since the question of (Gotta Do) has come up, you are rationally required to accept it. So you're rationally required to accept (Just Do It). So making (The Move) has the same rational status as accepting (Gotta Do) and (Just Do It). Just as the acceptance of these doesn't depend upon these further beliefs, making the transition in (The Move) doesn't depend upon these further beliefs. So, you can be rational in making the transition from believing that you ought to Φ to Φ-ing even if you also believe things that obviously entail that you shouldn't Φ.

I think that can't be right. Whether you ought to make the transition depends upon whether you ought to believe that you ought to Φ and that, says, the Humean depends upon your desires. I don't see that (The Move) is the move to make against the Humean.

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