It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change.

A man who dares to waste one hour of time has not discovered the value of life.

Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

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.

A man's friendships are one of the best measures of his worth.