as you may have noticed, i am an enemy of pleasure: not necessarily as an experience, but as a kind of uber-explanation of human behavior and certainly as the center of any sort of ethical theory. really a lot of the stuff i've seen in cognitive science and psychology just starts out with the flat assumption that only pleasure and pain can possibly motivate anyone to do anything. now, pointing up the problems with this would be a simple way of showing that a lot of the brain-image psychoscience of the current period cannot do without philosophy, and also is really ham-fisted and...wrong.
so: ok: after people shoot heroin, they want to keep shooting heroin. from this we conclude that shooting heroin is pleasurable (just like...taking a warm bath, cuddling, looking at gauguin's paintings, s&m, television, chocolate, horror movies, accomplishment etc: dude, are you kidding? you're going to start with the assumption that these are fundamentally identical experiences, or that they just must have something in common? reflect and start again.). anyway, shooting up must light up the 'pleasure center' of the brain, which is located relative to the rest of the brain as the entertainment aisle is located relative to the rest of the wal-mart. or it releases endorphins: the pleasure chemicals! you start with this question: what is the one explanation of why we do or want anything we do or want? since this is a bizarrely wrong question-begging question, everything that falls out after that is useless, or perhaps the word i'm groping for is 'false.' as old ludwig might say: don't assume they must have something in common, but look and see, or in this case, reflect.
now, i am a materialist and i think that mental states are identical to phsyical states (but on my view not only of the brain, but of the organism in the world). however, say there are such things as endorphins and they are released identically when you reach orgasm, finish writing your book, look at the earth from space, and listen to minor threat. that would not convince me that these are the same sorts of experiences or that i am seeking them for the same reasons. i don't think there is any one thing to be explained, so i'm not liable to be impressed by the explanations, and if you're telling me that the similar release of similar chemicals shows otherwise, i say you've got a long long way to go to nail that down at all. and if you're proving they're the same by brainscanning, i say this hasn't changed the way i think about these experiences at all or made them any more similar to one another than they were before. it might be an interesting result, but to see why we'd have to start with a lot richer encounter with and reflection on human experiences in a world.
really the brain research is completely compromised by the categories you start with, which are some kind of parade of cultural prejudices or ham-handed simplifications. this happens over and over in this sort of research on all kinds of questions. but you can't argue with science, you irrational tool! right, but that pleasure thing came from nowhere in the realm of science. it came from bentham or maybe oprah or maybe an absolut vodka ad.
what if there are many things people want, including many things that are not psychological states? what if there are many desirable and desired psychological states? 'pleasure,' once it encompasses all these experiences, is just a blank or variable meaning 'whatever people seek' or 'whatever psychological state people expect to get out of what they seek.' but now you've reified it into a thing, and as a thing to be explained, when really it should be a question that needs to be addressed before you go looking for it in people's heads. you have not gotten away without a prior theory or set of concepts, and also you've opted for an extremely primitive unidimensional taxonomy.
as the term is actually used, i think 'pleasure' might be ok for one dimension of the experience of taking a warm bath or eating milk, as opposed to dark, chocolate. i think for things like shooting heroin or having intense sex or looking at the earth from space, or running marathons, or working for decades to master the violin, you're just going to need entirely different accounts of motivation. but what these may be is not something you're going to find out with an mri. some beautiful things are pleasurable, but some are disturbing, awe-inspiring, challenging or induce despair and weeping instead of the vague grin and unfocused eyes of the pleasure-ridden.
centering pleasure like this is an artifact of the period when everything had to retreat into the subject, when nobody was in contact with anything but their own sensations (in my opinion, the brainy approach to psychology still labors under this devastating theoretical handicap). so if i wanted to know why you did what you did, i had to appeal exclusively to your internal states. you had a sensation/impression/idea and then a pleasure with regard to it. but no: desires, enjoyments etc are relations of human beings to stuff outside their heads. you can see the problem by the claim that both horror movies and pedicures must engage the same internal state insofar as people seek them out. start the other way round: with qualities of the object. then work up the relation. if you're going to do an mri scan, better scan the whole theater: the other people, the popcorn stand, the projector etc. no but we are concerned with what is actually accessible in the experience of the subject! dude, the popcorn stand out there in the lobby is actually accessible in the experience of the subject. really, deny that and then think about what you've just said and whether you actually believe it. otherwise you can't have any popcorn.
and here i'll just say it and try to pay off at a later date: a utilitarian moral theory that rests on hedonism is impossibly bad, just completely misguided. but to start with just think about what happens to a bentham/mill/sidgwick utilitarianism if - as is (er, obviously) the case - pleasure is not the only thing we seek and pain is not the only thing we avoid. well then 'happiness' construed as a life of much pleasure and little pain just is not the empirically-obvious real telos.
