I can remember the very spot in the road, whilst in my carriage, when to my joy the solution occurred to me.

In the struggle for survival, the fittest win out at the expense of their rivals because they succeed in adapting themselves best to their environment.

It is mere rubbish thinking, at present, of origin of life; one might as well think of origin of matter.

I am dying by inches, from not having any body to talk to about insects.

The following proposition seems to me in a high degree probable—namely, that any animal whatever, endowed with well-marked social instincts, the parental and filial affections being here included, would inevitably acquire a moral sense or conscience, as soon as its intellectual powers had become as well, or nearly as well developed, as in man. For, firstly, the social instincts lead an animal to take pleasure in the society of its fellows, to feel a certain amount of sympathy with them, and to perform various services for them.

It is like confessing to a murder.

Not one change of species into another is on record ... we cannot prove that a single species has been changed.