[Henri] Bergson, under the name of "intuition," has raised instinct to the position of sole arbiter of metaphysical truth. But in fact the opposition of instinct and reason is mainly illusory. Instinct, intuition, or insight is what first leads to the beliefs which subsequent reason confirms or confutes; but the confirmation, where it is possible, consists, in the last analysis, of agreement with other beliefs no less instinctive. Reason is a harmonizing, controlling force rather than a creative one. Even in the most purely logical realms, it is insight that first arrives at what is new.

Bertrand Russell

(from Our Knowledge of the External World, 1914)

Ever since becoming a socialist in childhood I had believed, as most socialists in those days did, in the inevitability of socialism. Indeed, there were quite a lot of non-socialists who believed in the inevitability of socialism. But one day, at the age of twenty-one or -two, I was sitting reading about Lenin in the history library at Oxford when suddenly the thought invaded my mind with almost traumatic clarity: ‘It’s never going to happen. There just isn’t ever actually going to be socialism.’ And once I realized this, it became obvious that no matter how attractive the idea might be, and no matter how good it would have been in practice if it could have come into existence, to advocate socialism was worse than useless because it meant being divorced from reality.

Bryan Magee (from Confessions of a Philosopher, 1997)