In the history of the human sciences, John Derbyshire notes, false trails and dead ends abound:
Two major world-historical intellectuals, Marx and Freud, as well as numerous minor ones, convinced themselves and millions of others that they had developed workable, rigorously scientific theories of human history or psychology, when in fact they had done nothing of the sort, only dressed up some pre-scientific concepts like sympathetic magic in ingenious and seductive vocabularies — the human-science equivalent of alchemy.