The Good and the Rationally Desirable
Jim Ryan, in a comment to a previous post, argues:
1.) There is nothing that would count as evidence that both(a.) X is not good for you; and (b.) X is most fulfilling to the largest and most coherent set of your desires, all the relevant non-normative facts being taken into account.
2.) If 1, then good is reducible to desire, namely rational desirability (where "rational" means coherent and fully informed as to the facts).
Therefore, the good is reducible to desire.
Some Comments/ Requests for Clarification
As I understand it (and maybe I don’t), Jim’s thesis is not merely that X is good iff X is rationally desirable, but that X’s being good is reducible to X’s being rationally desirable. Thus he is taking the biconditional to sanction a reduction: the good is nothing other than the rationally desirable. Jim holds this because he thinks that in every case in which X maximally fulfills a person P’s largest and most coherent set of desires, X is good for P, and vice versa.
I may be missing something, but this looks circular. The argument appears to boil down to this: the good = the rationally desirable because all and only good things are rationally desirable things.
(It is worth pointing out that every circular argument is valid, and some are even sound. It is just that a circular argument gives us no reason (independent of the argument’s conclusion) for accepting its conclusion. )
Another problem is this. The desirable is not the same as the desire-worthy. I am able to desire things that are not worthy of my desire. Suppose a man desires sex with a different woman every night. (That is, a woman different from the woman of every previous night, as opposed to alternating between or among n women, where n is a small number like 2 or 3 or 4) It follows that he is able to desire sex with a different woman every night. It does not follow, however, that enjoying such a sexual feast is desirable in the normative sense, i.e., that it is desire-worthy. I am sure Jim is aware of the equivocity of ‘desirable.’ The great J. S. Mill, however, was bamboozled by a close cousin of it. See here.
Of course, Jim spoke of the rationally desirable, not of the desirable simpliciter. I concede that it might not be rationally desirable for a given person to have sex every night with a different woman because then the coherence condition might not be met. (If I desire a long-term close relation, then fidelity to one partner may be required.)
Can rationality bring us from the nonnormatively desirable to the normatively desire-worthy? I don’t see that it can, and I don’t think Jim is asserting that it can. He is simply identifying the good with the rationally desirable. But then doesn’t Jim face G. E. Moore’s Open Question argument? Suppose someone says that pleasure is the good. Surely that is not an analytic proposition. So the connection between pleasure and the good is synthetic. But then can’t we reasonably ask: Is pleasure the good? Doesn’t this remain an open question?
Identifying goodness with rational desirability is like identifying truth with rational acceptability. In both cases, relativism results. Both rational desirability and rational acceptability vary from person to person, place to place, and time to time. If anyone needs examples, I can supply them. But truth is surely absolute. I would say the same for what is genuinely desire-worthy for human beings. Of course, I need to argue this out in great detail.
Let me end this set of comments by giving a possible example of something rationally desirable by a person that is not good for a person. Suppose Jack is 18 yrs old and is such that his largest coherent set of desires at the time would be best fulfilled by marrying Jill. Suppose Jack has done his level best to inform himself of all relevant facts. Still, it may be that there are facts about himself, about Jill, and about the world at large that Jack’s father knows, but Jack is incapable of knowing due to immaturity, love-blindness, etc. I would not conclude that what 18 year old Jack rationally desires, or is rationally able to desire, is identical to the good for Jack. He may not know his true good!
Jim will understand that this is not intended as a refutation, but as an invitation to clarification and further discussion.