A fairly bright boy is far more intelligent and far better company than the average adult.

I will jump into the river to save two brothers or eight cousins.

I have never yet met a healthy person who worried very much about his health, or a really good person who worried much about his own soul.

I have come to the conclusion that my subjective account of my motivation is largely mythical on almost all occasions. I don't know why I do things.

Quantitative work shows clearly that natural selection is a reality, and that, among other things, it selects Mendelian genes, which are known to be distributed at random through wild populations, and to follow the laws of chance in their distribution to offspring. In other words, they are an agency producing variation of the kind which Darwin postulated as the raw material on which selection acts.

Teleology is like a mistress to a biologist: he cannot live without her but he's unwilling to be seen with her in public.

To the biologist the problem of socialism appears largely as a problem of size.