Via Chris Dillow, I discover a finance professor disputing the "strict classic economists [who] have argued that charity and other selfless acts do not make economic sense." Helping other people can be rational, he insists. Why? Apparently, because it will give you a warm glow. (He quotes evidence that "individuals report significantly greater happiness if they make charitable donations or give gifts to others rather than spending on themselves".)
The implication seems to be that if it weren't for the warm glow -- if we imagine someone who really wouldn't get any personal benefit or welfare boost from helping others -- then, upon seeing others in need, it would be "irrational" for this person to help them. See the neighbour's kid drowning? Fortunately, most of us would get enough of a warm glow to make saving their life rationally permissible. But for the others, they're apparently not thinking straight if they let such a distraction trump their personal desire to watch TV.
Actually, it gets worse. Most of us unthinkingly comply with the obligation not to murder. But if you one day find yourself in a position where a surreptitious poisoning could safely advance your interests (broadly construed: we're not just talking about money, as the prof. says, but 'warm glows' too), and you wouldn't feel any guilt about it, why, it must be downright "irrational" to let dispassionate moral considerations get in your way.
I take it nobody actually believes this. But it's strange, then, how many give lip service to the theory that implies it. Presumably they just haven't thought through the implications; but I have trouble seeing even a prima facie motivation for identifying rationality with self-interest. Why would you ever think that the only relevant considerations, in deciding how to act, are the consequences for oneself? If an action will affect other people too, it seems plain that this, too, might merit - or even require - consideration. But the above view implies that not only is such a blinkered assessment rationally permissible (already a dubious claim), but it's outright impermissible to consider anyone or anything besides oneself. How could a view this loopy be so widespread?