It is useful that while mankind are imperfect there should be different opinions, so is it that there should be different experiments of living; that free scope should be given to varieties of character, short of injury to others.
John Stuart MillWe have a right, also, in various ways, to act upon our unfavorable opinion of anyone, not to the oppression of his individuality, but in the exercise of ours.
John Stuart MillSince the general or prevailing opinion on any subject is rarely or never the whole truth, it is only by the collision of adverse opinion that the remainder of the truth has any chance of being supplied.
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 Mill