What harm is there in believing in things that are not literally true?
The danger to society is not merely that it should believe wrong things, though that is great enough; but that it should become credulous, and lose the habit of testing things and inquiring into them, for then it must sink back into savagery… It may matter little to me, in my cloud-castle of sweet illusions and darling lies; but it matters much to Man that I have made my neighbors ready to deceive. The credulous man is father to the liar and the cheat.
- W.H. Clifford, The Ethics of Belief