It is the business of the future to be dangerous; and it is among the merits of science that it equips the future for its duties.

A clash of doctrine is not a disaster, it is an opportunity.

Life is complex in its expression, involving more than percipience, namely desire, emotion, will, and feeling.

Life is the enjoyment of emotion, derived from the past and aimed at the future.

Error is the price we pay for progress.

Speak out in acts; the time for words has passed, and only deeds will suffice.

Nature gets credit which should in truth be reserved for ourselves: the rose for its scent, the nightingale for its song; and the sun for its radiance. The poets are entirely mistaken. They should address their lyrics to themselves and should turn them into odes of self congratulation on the excellence of the human mind.