When I view all beings not as special creations, but as the lineal descendants of some few beings which lived long before the first bed of the Cambrian system was deposited, they seem to me to become ennobled.

It is a fatal fault to reason whilst observing, though so necessary beforehand and so useful afterwards.

As for a future life, every man must judge for himself between conflicting vague probabilities.

If a person asked my advice, before undertaking a long voyage, my answer would depend upon his possessing a decided taste for some branch of knowledge, which could by this means be advanced. No doubt it is a high satisfaction to behold various countries and the many races of mankind, but the pleasures gained at the time do not counterbalance the evils.

Nothing is easier than to admit in words the truth of the universal struggle for life, or more difficult--at least I have found it so--than constantly to bear this conclusion in mind.

Freedom of thought is best promoted by the gradual illumination of men’s minds which follows from the advance of science.

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