It is not true that a man can believe or disbelieve what he will. But it is certain that an active desire to find any proposition true will unconsciously tend to that result by dismissing importunate suggestions which run counter to the belief, and welcoming those which favor it. The psychological law, that we only see what interests us, and only assimilate what is adapted to our condition, causes the mind to select its evidence.

Problems of Life and Mind (ed. 1874)