Friendship involves many things but, above all the power of going outside oneself and appreciating what is noble and loving in another.

It is better to read a little and thoroughly than cram a crude undigested mass into my head, though it be great in quantity.

Each such answer to the great question, invariably asserted by the followers of its propounder, if not by himself, to be complete and final, remains in high authority and esteem, it may be for one century, or it may be for twenty: but, as invariably, Time proves each reply to have been a mere approximation to the truth tolerable chiefly on account of the ignorance of those by whom it was accepted, and wholly intolerable when tested by the larger knowledge of their successors.

The birth of science was the death of superstition.

Nothing can be more incorrect than the assumption one sometimes meets with, that physics has one method, chemistry another, and biology a third.

The great thing in the world is not so much to seek happiness as to earn peace and self-respect.

Misery is a match that never goes out.