Analysis of information sources in references of the Wikipedia article "George Gaylord Simpson" in English language version.
By his early teens, Simpson had given up being a Christian, although he had not formally declared himself an atheist. At college he began the gradual development of what might best be called positivistic agnosticism: a belief that the world could be known and explained by ordinary empirical observation without recourse to supernatural forces. Ultimate causation, he considered unknowable.