“Take the question whether other people exist. …It is plain that it makes for happiness to believe that they exist – for even the greatest misanthropist would not wish to be deprived of the objects of his hate. Hence the belief that other people exist is, pragmatically, a true belief. But if I am troubled by solipsism, the discovery that a belief in the existence of others is 'true' in the pragmatist's sense is not enough to allay my sense of loneliness: the perception that I should profit by rejecting solipsism is not alone sufficient to make me reject it. For what I desire is not that the belief in solipsism should be false in the pragmatic sense, but that other people should in fact exist. And with the pragmatist's meaning of truth, these two do not necessarily go together. The belief in solipsism might be false even if I were the only person or thing in the universe.”

1950s, Atoms for Peace (1953)

Part 3, Chapter 1.
Books, Coningsby (1844), Contarini Fleming (1832)

Source: Faith vs. Fact (2015), p. 182

Treason (1988)

Source: Time Tunnel (1964), Chapter 1 (p. 8).

The Anatomy of Loneliness (1941)

The Ethics of Belief (1877), The Duty of Inquiry
Context: No man holding a strong belief on one side of a question, or even wishing to hold a belief on one side, can investigate it with such fairness and completeness as if he were really in doubt and unbiased; so that the existence of a belief not founded on fair inquiry unfits a man for the performance of this necessary duty.
Nor is it that truly a belief at all which has not some influence upon the actions of him who holds it. He who truly believes that which prompts him to an action has looked upon the action to lust after it, he has committed it already in his heart. If a belief is not realized immediately in open deeds, it is stored up for the guidance of the future. It goes to make a part of that aggregate of beliefs which is the link between sensation and action at every moment of all our lives, and which is so organized and compacted together that no part of it can be isolated from the rest, but every new addition modifies the structure of the whole. No real belief, however trifling and fragmentary it may seem, is ever truly insignificant; it prepares us to receive more of its like, confirms those which resembled it before, and weakens others; and so gradually it lays a stealthy train in our inmost thoughts, which may someday explode into overt action, and leave its stamp upon our character for ever.

Beyond Belief conference (November 2006)

Quote from The Power of Mystery (7 December 1957), a London Observer interview with John Richardson, as quoted in Braque: The Late Works (1997), by John Golding, Introduction, p. 10
unsourced variant translation: I made a great discovery. I don't believe in anything anymore. Objects do not exist for me, except that there is a harmonious relationship among them, and also between them and myself. When one reaches this harmony, one reaches a sort of intellectual void. This was everything becomes possible, everything becomes legitimate, and life is a perpetual revelation. This is true song.
1946 - 1963