Truth gains more even by the errors of one who, with due study and preparation, thinks for himself, than by the true opinions of those who only hold them because they do not suffer themselves to think.
John Stuart MillLord, enlighten thou our enemies. Sharpen their wits, give acuteness to their perceptions, and consecutiveness and clearness to their reasoning powers: we are in danger from their folly, not from their wisdom; their weakness is what fills us with apprehension, not their strength.
John Stuart MillIt must be granted that in every syllogism, considered as an argument to prove the conclusion, there is a petitio principii. When we say, All men are mortal Socrates is a man therefore Socrates is mortal; it is unanswerably urged by the adversaries of the syllogistic theory, that the proposition, Socrates is mortal.
John Stuart Mill