1. “All truth, in the long run, is only common sense clarified.”
2. “A man's worst difficulties begin when he is able to do as he likes.”
3. “A world of facts lies outside and beyond the world of words.”
4. "Cinderella [Science]... lights the fire, sweeps the house, and provides the dinner; and is rewarded by being told that she is a base creature, devoted to low and material interests. But in her garret she has fairy visions out of the ken of the pair of shrews [Theology and Philosophy] who are quarrelling downstairs. She sees the order which pervades the seeming disorder of the world; the great drama of evolution, with its full share of pity and terror, but also with abundant goodness and beauty... ; and she learns... that the foundation of morality is to [be] done, once and for all, with lying; to give up pretending to believe that for which there is no evidence, and repeating unintellegible propositions about thing beyond the possibilities of knowledge"
5. “Every great advance in natural knowledge has involved the absolute rejection of authority.”
6. “Follow humbly wherever and to whatever abyss Nature leads, or you shall learn nothing.”
7. “I am too much of a skeptic to deny the possibility of anything.”
8. "If a little knowledge is dangerous, where is the man who has so much as to be out of danger?"
9. “If you go buzzing about between right and wrong, vibrating and fluctuating, you come out nowhere; but if you are absolutely and thoroughly and persistently wrong, you must, some of these days, have the extreme good fortune of knocking your head against a fact, and that sets you all straight again.”
10. “Irrationally held truths may be more harmful than reasoned errors.”
11. “It is a popular delusion that the scientific enquirer is under an obligation not to go beyond generalisation of observed facts...but anyone who is practically acquainted with scientific work is aware that those who refuse to go beyond the facts, rarely get as far.”
12. “Science is nothing but trained and organized common sense differing from the latter only as a veteran may differ from a raw recruit: and its methods differ from those of common sense only as far as the guardsman's cut and thrust differ from the manner in which a savage wields his club.”
13. ”Science is simply common sense at its best.”
14. "Sit down before fact like a little child, and be prepared to give up every preconceived notion. Follow humbly wherever and to whatever abyss Nature leads, or you shall learn nothing."
15. “The chess-board is the world; the pieces are the phenomena of the universe; the rules of the game are what we call the laws of Nature. The player on the other side is hidden from us. We know that his play is always fair, and patient. But also we know, to our cost, that he never overlooks a mistake, or makes the smallest allowance for ignorance.”
16. "The foundation of morality is to... give up pretending to believe that for which there is no evidence, and repeating unintelligible propositions about things beyond the possibilities of knowledge."
17. “The great end of life is not knowledge, but action. What men need is as much knowledge as they can organize for action; give them more and it may become injurious. Some men are heavy and stupid from undigested learning.”
18. “The great tragedy of science, the slaying of a beautiful theory by an ugly fact.”
19. “The known is finite, the unknown infinite; intellectually we stand on an islet in the midst of an illimitable ocean of inexplicability. Our business in every generation is to reclaim a little more land, to add something to the extent and solidity of our possessions.”
20. ”There is no greater mistake than the hasty conclusion that opinions are worthless because they are badly argued.”
21. “There is the greatest practical benefit in making a few failures early in life.”
22. “The rung of a ladder was never meant to rest upon, but only to hold a man's foot:long enough to enable him to put the other somewhat higher.”
23. ”Try to learn something about everything and everything about something.”
