There is nothing of permanent value (putting aside a few human affections) nothing that satisfies quiet reflection--except the sense of having worked according to one's capacity and light to make things clear and get rid of cant and shams of all sorts.

In the world of letters, learning and knowledge are one, and books are the source of both; whereas in science, as in life, learning and knowledge are distinct, and the study of things, and not of books, is the source of the latter.

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

Make up your mind to act decidedly and take the consequences. No good is ever done in this world by hesitation.

Every philosophical thinker hails it [The Origin of Species] as a veritable Whitworth gun in the armoury of liberalism.

For every man the world is as fresh as it was at the first day, and as full of untold novelties for him who has the eyes to see them.

It is wrong for a man to say that he is certain of the objective truth of any proposition unless he can produce evidence which logically justifies that certainty. This is what Agnosticism asserts; and, in my opinion, it is all that is essential to Agnosticism. That which Agnostics deny and repudiate, as immoral, is the contrary doctrine, that there are propositions which men ought to believe without logically satisfactory evidence; and that reprobation ought to attach to the profession of disbelief in such inadequately supported propositions.