It is not to be forgotten that what we call rational grounds for our beliefs are often extremely irrational attempts to justify our instincts.

I take it that the good of mankind means the attainment, by every man, of all the happiness which he can enjoy without diminishing the happiness of his fellow men.

I am content with nothing, restless and ambitious... and I despise myself for the vanity, which formed half the stimulus to my exertions. Oh would that I were one of those plodding wise fools who having once set their hand to the plough go on nothing doubting.

Science is nothing, but trained and organized common sense.

Of moral purpose I see no trace in Nature. That is an article of exclusively human manufacture and very much to our credit.

Science is organized common sense where many a beautiful theory was killed by an ugly fact.

Try to learn something about everything and everything about something.