“Knowledge comes only to those who despise happiness.”

Source: Profiles of the Future: An Inquiry into the Limits of the Possible

#40541, Part 41
Seventy Seven Thousand Service-Trees series 1-50 (1998)

Source: On the Bondage of the Will (1525), p. 168

"A Liberal Decalogue" http://www.panarchy.org/russell/decalogue.1951.html, from "The Best Answer to Fanaticism: Liberalism", New York Times Magazine (16/December/1951); later printed in The Autobiography of Bertrand Russell (1969), vol. 3: 1944-1967, pp. 71-2
1950s
Context: The Ten Commandments that, as a teacher, I should wish to promulgate, might be set forth as follows:
1. Do not feel absolutely certain of anything.
2. Do not think it worth while to proceed by concealing evidence, for the evidence is sure to come to light.
3. Never try to discourage thinking for you are sure to succeed.
4. When you meet with opposition, even if it should be from your husband or your children, endeavour to overcome it by argument and not by authority, for a victory dependent upon authority is unreal and illusory.
5. Have no respect for the authority of others, for there are always contrary authorities to be found.
6. Do not use power to suppress opinions you think pernicious, for if you do the opinions will suppress you.
7. Do not fear to be eccentric in opinion, for every opinion now accepted was once eccentric.
8. Find more pleasure in intelligent dissent that in passive agreement, for, if you value intelligence as you should, the former implies a deeper agreement than the latter.
9. Be scrupulously truthful, even if the truth is inconvenient, for it is more inconvenient when you try to conceal it.
10. Do not feel envious of the happiness of those who live in a fool's paradise, for only a fool will think that it is happiness.

Source: The Purpose Driven Life: What on Earth Am I Here for?

Source: The enjoyments of life (such was now my theory) are sufficient to make it a pleasant thing, when they are taken en passant, without being made a principal object. Once make them so, and they are immediately felt to be insufficient. They will not bear a scrutinizing examination. Ask yourself whether you are happy, and you cease to be so. The only chance is to treat, not happiness, but some end external to it, as the purpose of life. Let your self-consciousness, your scrutiny, your self-interrogation, exhaust themselves on that; and if otherwise fortunately circumstanced you will inhale happiness with the air you breathe, without dwelling on it or thinking about it, without either forestalling it in imagination, or putting it to flight by fatal questioning. This theory now became the basis of my philosophy of life. And I still hold to it as the best theory for all those who have but a moderate degree of sensibility and of capacity for enjoyment; that is, for the great majority of mankind."

Autobiography, Ch 5, https://www.gutenberg.org/files/10378/10378-h/10378-h.htm#link2H_NOTE https://www.laits.utexas.edu/poltheory/mill/auto/auto.c05.html source: Autobiography (1873), Ch. 5: A Crisis in My Mental History (p. 100)

Source: The Woman in the Dunes

Source: 1960s, Continuities in Cultural Evolution (1964), p. 321