Scientists, including those who speak most eloquently to the public, are continually saying "We must known more." This is true, of course, but the muted conviction that this in itself will save us is false. Knowledge does not automatically order itself in human terms, and if this is true of science generally, it is all the more true of the sciences of human behavior. More startling, and contrary to the workaday beliefs of most scientists, knowledge does not even always accumulate, in the simplest, additive sense. A few years ago a colleague of mine came back from a conference on information retrieval where one of the speakers argued (using, of course, calculation) that for some of the knowledge unearthed by scientists of the past, it would be cheaper to rediscover it than to retrieve it. Imagine, if you will, the wave of uneasy movement that might have rippled through the graves of dead scientists at that argument: For some, the work to which they devoted their lives was not merely wrongheadedthis they were prepared forit was, even when right, never absorbed in the body of human knowledge.