Many, including Huxley, Hooker, and Darwin himself, were highly critical of these ideas. As one historian of science has pointed out, Wallace's views in this area were at odds with two major tenets of Darwinism. These are: evolution does not have a goal, and it is not aimed at or centered around mankind. It is thought by most biographers that his thinking on the evolution of man was influenced by his adoption of spiritualism, which happened at the same time.