An article in the New England Journal of Medicine for February 23 reviews the current state of knowledge of the genetics of mental handicap and autism, with brief mention of schizophrenia and epilepsy in the bargain. Considering the history of this subject, ethical considerations are conspicuous by their absence from this article. After all, the premature assumption of knowledge of the genetics of mental handicap, mental illness, and epilepsy was one of the major ingredients of the Nazi program to kill 100,000 patients (as being “unworthy of life”) in German mental hospitals: a program that, as we now know, was a rehearsal for the Holocaust.

But one cannot prohibit the attempt to obtain new knowledge because the false assumption of knowledge about it in the past was used unethically. Even if he who does not remember the past is not absolutely condemned to repeat it, he is probably more likely to do so.

Nevertheless, an astonishing amount has been learned in recent years, and the pace is accelerating. This is a field in which the Promethean bargain is coming to fruition. But it is still necessary to remain cautious.