No amount of observations of white swans can allow the inference that all swans are white, but the observation of a single black swan is sufficient to refute that conclusion.
David HumeMohammed praises [instances of] tretchery, inhumanity, cruelty, revenge, and bigotry that are utterly incompatible with civilized society.
David HumeCustom, then, is the great guide of human life. It is that principle alone, which renders our experience useful to us, and makes us expect, for the future, a similar train of events with those which have appeared in the past.
David Hume