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.

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.

It was a reaction from the old idea of "protoplasm", a name which was a mere repository of ignorance.

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

While I do not suggest that humanity will ever be able to dispense with its martyrs, I cannot avoid the suspicion that with a little more thought and a little less belief their number may be substantially reduced.

I am quite sure that our views on evolution would be very different had biologists studied genetics and natural selection before and not after most of them were convinced that evolution had occurred.

If human beings could be propagated by cutting, like apple trees, aristocracy would be biologically sound.