In talking to younger psychologists, one finds that many of them seem to believe that perception is something at the surface of the mind, a kind of borderline problem, and that preoccupation with it is obsolete. They look with disdain at every psychological problem that does not at least deal with personality, motivation, or social intercourse. But when discussing problems in which simple facts of stimulus and reaction play a role, as for example in behavior therapy, they prove that they would have done well to occupy themselves a little more with the fundamentals of perception.