Although he was nonreligious, Wallace attributed humanity’s surplus brain power to the “unseen universe of Spirit.” Nothing less could account for the human soul. Unsurprisingly, Darwin was deeply disturbed to see his respected colleague invoke the hand of God, in however camouflaged a way. There was absolutely no need for supernatural explanations, he felt. Nevertheless, Wallace’s Problem still looms large in academic circles eager to keep the human mind out of the clutches of biology.
