Beliefs are based much more on custom and example than on any certain knowledge

Having learnt from the time I was at school that there is nothiing one can imagine so strange or so unbelievable that has not been said by one or other of the philosophers; and since then, while travelling, having recognized that all those who hold opinions quite opposed to ours are not on that account barbarians or savages, but that many exercise as much reason as we do, or more; and having considered how a given man, with his given mind, being brought up from childhood among the French or Germans, becomes different from what he would be if he had always lived among the Chinese or among cannibals; and how, down to our very fashions in dress, what pleased us ten years ago and will perhaps please us again before another ten years are out, now seems to us extravagant and laughable, I was convinced that our beliefs are based much more on custom and example than on any certain knowledge, and, nevertheless that the assent of many voices is not a valid proof for truths which are rather difficult to discover, because they are much more likely to be found by one single man than by a whole people. Thus I could not choose anyone whose opinions it seemed to me I ought to prefer to those of others, and I found myself constrained, as it were, to undertake my own guidance.

René Descartes, Discourse on Method and The Meditations (Penguin Classics, 1968) p. 39