I had found again and again that the most aberrant population of a species – often having reached species rank, and occasionally classified even as a separate genus – occurred at a peripheral location, indeed usually at the most isolated peripheral location.

I feel that one species, mankind, doesn’t have the right to exterminate.

Our understanding of the world is achieved more effectively by conceptual improvements than by discovery of new facts.

The most consequential change in man’s view of the world, of living nature and of himself came with the introduction, over a period of some 100 years beginning only in the 18th century, of the idea of change itself, of change over periods of time: in a word, of evolution.

I have the honesty to say I’m an Atheist. There is nothing that supports the idea of a personal God.

Every politician, clergyman, educator, or physician, in short, anyone dealing with human individuals, is bound to make grave mistakes if he ignores these two great truths of population zoology: (1) no two individuals are alike, and (2) both environment and genetic endowment make a contribution to nearly every trait.

I have the honesty to say I'm an Atheist. There is nothing that supports the idea of a personal God.

The history of science knows scores of instances where an investigator was in the possession of all the important facts for a new theory but simply failed to ask the right questions.

On the other hand, famous evolutionists such as Dobzhansky were firm believers in a personal God. He would work as a scientist all week and then on Sunday get down on his knees and pray to God. Frankly I've never been able to understand it because you would need two totally different compartments in your brain, one that deals with religion and the other with everything else.

most scientific problems are far better understood by studying their history than their logic.