Three strengths of desire

Plausibly, having satisfied desires contributes to my well-being and having unsatisfied desires contributes to my ill-being, at least in the case of rational desires. But there are infinitely many things that I’d like to know and only finitely many that I do know, and my desire here is rational. So my desire and knowledge state contributes infinite misery to me. But it does not. So something’s gone wrong.

That’s too quick. Maybe the things that I know are things that I more strongly desire to know than the things that I don’t know, to such a degree that the contribution to my well-being from the finite number of things I know outweighs the contribution to my ill-being from the infinite number of things I don’t know. In my case, I think this objection holds, since I take myself to know the central truths of the Christian faith, and I take that to make me know things that I most want to know: who I am, what I should do, what the point of my life is, etc. And this may well outweigh the infinitely many things that I don’t know.

Yes, but I can tweak the argument. Consider some area of my knowledge. Perhaps my knowledge of noncommutative geometry. There is way more that I don’t know than that I know, and I can’t say that the things that I do know are ones that I desire so much more strongly to know than the ones I don’t know so as to balance them out. But I don’t think I am made more miserable by my desire and knowledge state with respect to noncommutative geometry. If I neither knew anything nor cared to know anything about noncommutative geometry, I wouldn’t be any better off.

Thinking about this suggests there are three different strengths in a desire:

1. S_p: preferential strength, determined by which things one is inclined to choose over which.

2. S_h: happiness strength, determined by how happy having the desire fulfilled makes one.

3. S_m: misery strength, determined by how miserable having the desire unfulfilled makes one.

It is natural to hypothesize that (a) the contribution to well-being is S_h when the desire is fulfilled and −S_m when it is unfulfilled, and (b) in a rational agent, S_p = S_h + S_m. As a result of (b), one can have the same preferential strength, but differently divided between the happiness and misery strengths. For instance, there may be a degree of pain such that the preferential strength of my desire not to have that pain equals the preferential strength of my desire to know whether the Goldbach Conjecture is true. I would be indifferent whether to avoid the pain or learn whether the Goldbach Conjecture is true. But they are differently divided: in the pain case S_m >> S_h and in the Goldbach case S_m << S_h.

There might be some desires where S_m = 0. In those cases we think “It would be nice…” For instance, I might have a desire that some celebrity be my friend. Here, S_m = 0: I am in no way made miserable by having that desire be unfulfilled, although the desire might have significant preferential strength—there might be significant goods I would be willing trade for that friendship. On the other hand, when I desire that a colleague be my friend, quite likely S_m >> 0: I would pine if the friendship weren’t there.

(We might think a hedonist has a story about all this: S_h measures how pleasant it is to have the desire fulfilled and S_m measures how painful the unfulfilled desire is. But that story is mistaken. For instance, consider my desire that people not say bad things behind my back in such a way that I never find out. Here, S_m >> 0, but there is no pain in having the desire unfulfilled, since when it’s unfulfilled I don’t know about it.)