Science is simply common sense at its best, that is, rigidly accurate in observation, and merciless to fallacy in logic.

It is because the body is a machine that education is possible. Education is the formation of habits, a superinducing of an artificial organization upon the natural organization of the body.

It ought not to be unpleasant to say that which one honestly believes or disbelieves. That it so constantly is painful to do so, is quite enough obstacle to the progress of mankind in that most valuable of all qualities, honesty of word or of deed.

Science reckons many prophets, but there is not even a promise of a Messiah.

The facts of variability, of the struggle for existence, of adaptation to conditions, were notorious enough; but none of us had suspected that the road to the heart of the species problem lay through them, until Darwin and Wallace dispelled the darkness.

Education is the instruction of the intellect in the laws of Nature, under which name I include not merely things and their forces, but people and their ways; and the fashioning of the affections and of the will into an earnest and loving desire to move in harmony with those laws.

Natural knowledge, seeking to satisfy natural wants, has found the ideas which can alone still spiritual cravings. I say that natural knowledge, in desiring to ascertain the laws of comfort, has been driven to discover those of conduct, and to lay the foundations of a new morality.