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

...the self-satisfied dogmatism with which mankind at each period of its history cherishes the delusion of the finality of existing modes of knowledge.

Everything of importance has been said before by somebody who did not discover it.

Philosophy is the product of wonder.

You think the world is what it looks like in fine weather at noon day; I think it is what it seems like in the early morning when one first wakes from deep sleep.

Civilization advances by extending the number of important operations which we can perform without thinking of them.

The race that does not value trained intelligence is doomed.