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 HumeIt is more rational to suspect knavery and folly than to discount, at a stroke, everything that past experience has taught me about the way things actually work
David HumeLet us become thoroughly sensible of the weakness, blindness, and narrow limits of human reason: Let us duly consider its uncertainty and endless contrarieties, even in subjects of common life and practice.... When these topics are displayed in their full light, as they are by some philosophers and almost all divines; who can retain such confidence in this frail faculty of reason as to pay any regard to its determinations in points so sublime, so abstruse, so remote from common life and experience?
David HumeThe conduct of a man, who studies philosophy in this careless manner, is more truly sceptical than that of any one, who feeling inhimself an inclination to it, is yet so over-whelm'd with doubts and scruples, as totally to reject it. A true sceptic will be diffident of his philosophical doubts, as well as of his philosophical conviction; and will never refuse any innocent satisfaction, which offers itself, upon account of either of them.
David HumeAccurate and just reasoning is the only catholic remedy, fitted for all persons and all dispositions; and is alone able to subvert that abstruse philosophy and metaphysical jargon, which, being mixed up with popular superstition, renders it in a manner impenetrable to careless reasoners, and gives it the air of science and wisdom.
David Hume