George Gaylord Simpson said this quote

If I didn't fear I'd do you harm...I'd try to make you an atheist. I really do think that you are a deluded follower of mistaken and superstitious and cowardly theories. That's as far as I'll go....Everyone who worships a god worships a force back of all nature, no matter what they call him or it and even if they call his aspects by different names & have many gods. If there really is such a force, then all people who worship any god or gods, worship the same god. I'd just as soon call him Ishtar or Baal or Jehovah. They're merely names for the same idea. (Letter from Simpson to Anne Roe, written ca. 1920-21, when Anne was briefly flirting with fundamentalist Christianity, American Philosophical Society archives.)

~ George Gaylord Simpson

Man is the result of a purposeless and natural process that did not have him in mind.

~ George Gaylord Simpson

To put it crudely but graphically, the monkey who did not have a realistic perception of the tree branch he jumped for was soon a dead monkey—and therefore did not become one of our ancestors.

~ George Gaylord Simpson

Man has risen, not fallen. He can choose to develop his capacities as the highest animal and to try to rise still farther, or he can choose otherwise. The choice is his responsibility, and his alone. There is no automatism that will carry him upward without choice or effort and there is no trend solely in the right direction. Evolution has no purpose; man must supply this for himself. The means to gaining right ends involve both organic evolution and human evolution, but human choice as to what are the right ends must be based on human evolution.

~ George Gaylord Simpson