|Economists play a bait and switch game.
The basic idea concerning human choice _is_ tautological: people do
what they want to do. (How can you tell what someone's preferences
are? simple, revealed preference, i.e., what they do.)
But there is another version, which appears in textbooks and lectures,
of the simple-minded maximizer of a given utility function who doesn't
care about others' utility, etc. This radical individualist is at the
center of the economists' conception, but when attacked, he falls back
on the tautological version. This is the bait and switch.
The old econ. vision of humanity should go away, if we're lucky, now
that experimental (or behavioral) economics is becoming popular. It
turns out (from the research of the guy in the office next door to
mine) that people have a built-in sense of what's fair (a social
notion that's totally missed by homo economicus).
More, we have to look to where "preferences" or goals come from. This
suggests that sociology should be seen as complementary to the
goal-seeking behavior posited by economics.
There's also the psychodynamic perspective (the broadly defined
psychoanalysic view), in which human choice is a product of an
internal conflict of motives (ego vs. id vs. superego).