Mathematics seems to endow one with something like a new sense.

The expression often used by Mr. Herbert Spencer of the Survival of the Fittest is more accurate, and is sometimes equally convenient.

I have called this principle, by which, each slight variation, if useful, is preserved, by the term of Natural Selection.

a lot of thinking, mathematics and talk.

The very essence of instinct is that it's followed independently of reason.

We can allow satellites, planets, suns, universe, nay whole systems of universes, to be governed by laws, but the smallest insect, we wish to be created at once by special act.