The attempt to discover and promulgate the truth is nevertheless an obligation upon all scientists, one that must be persevered in no matter what the rebuffs—for otherwise what is the point in being a scientist?

I cannot give any scientist of any age better advice than this: the intensity of a conviction that a hypothesis is true has no bearing over whether it is true or not.

Innocent, unbiased observation is a myth.

I once spoke to a human geneticist who declared that the notion of intelligence was quite meaningless, so I tried calling him unintelligent. He was annoyed, and it did not appease him when I went on to ask how he came to attach such a clear meaning to the notion of lack of intelligence. We never spoke again.

If politics is the art of the possible, research is surely the art of the soluble. Both are immensely practical-minded affairs.

Heredity proposes and development disposes.

I believe in intelligence, and I believe also that there are inherited differences in intellectual ability, but I do not believe that intelligence is a simple scalar endowment that can be quanitified by attaching a single figure to it—an I.Q. or the like.