The Nazis killed millions. Their justification was psychiatry and psychology’s theory of eugenics—that certain people were inferior and should be exterminated and their kind bred out of the race. In November 2010, Dr. Frank Schneider, president of the German Association of Psychiatrists issued a public apology for psychiatry’s creation of the ideology that developed Nazi euthanasia and their role in the selection of those to be murdered as well as murdering others themselves. German psychiatrists created the “racial hygiene” movement, which began with the work of eugenicist Alfred Ploetz in 1895. The idea stemmed from English psychologist Francis Galton who...