Quote from : Institutes of the Christian Religion Book

Were the judgments of mankind correct, custom would be regulated by the good. But it is often far otherwise in point of fact; for, whatever the many are seen to do, forthwith obtains the force of custom. But human affairs have scarcely ever been so happily constituted as that the better course pleased the greater number. Hence the private vices of the multitude have generally resulted in public error, or rather that common consent in vice which these worthy men would have to be law.