He must be able to hear them [the counter arguments] from persons who actually believe them; who defend them in earnest, and do their very utmost for them. He must know them in their most plausible and persuasive form; he must feel the whole force of the difficulty which the true view of the subject has to encounter and dispose of; else he will never really possess himself of the portion of truth which meets and removes that difficulty.
John Stuart MillA being who can create a race of men devoid of real freedom and inevitably foredoomed to be sinners, and then punish them for being what he has made them, may be omnipotent and various other things, but he is not what the English language has always intended by the adjective holy.
John Stuart MillHowever unwillingly a person who has a strong opinion may admit the possibility that his opinion may be false, he ought to be moved by the consideration that, however true it may be, if it is not fully, frequently, and fearlessly discussed, it will be held as a dead dogma, not a living truth.
John Stuart MillIn proportion to the development of his individuality, each person becomes more valuable to himself, and is therefore capable of being more valuable to others. . . .
John Stuart Mill