"Fear of serious injury cannot alone justify oppression of free speech and assembly. Men feared witches and burnt women. It is the function of free speech to free men from the bondage of irrational fears. ... discussion affords ordinarily adequate protection against the dissemination of noxious doctrine; that the greatest menace to freedom is an inert people; that public discussion is a political duty; ... that the path of safety lies in the opportunity to discuss freely supposed grievances and proposed remedies; and that the fitting remedy for evil counsels is good ones."3 (Brandeis, J.)
"He that is strongly of any opinion must suppose (unless he be self-condemned) that his persuasion is built upon good grounds, and that his assent is no greater than what the evidence of the truth he holds forces him to; and that they are arguments, and not inclination of fancy, that make him so confident and positive in his tenets. Now if, after all his profession, he cannot bear any opposition to his opinion - if he cannot so much as give a patient hearing, much less examine and weigh arguments on the other side - does he not plainly confess it is prejudice governs him? And it is not the evidence of truth, but some lazy anticipation, some beloved presumption, that he desires to rest undisturbed in. For if what he holds be as he give out, well fenced with evidence, and he sees it to be true, what need he fear to put it to the proof? If his opinion be settled upon a firm foundation, if the arguments that support it, and have obtained his assent, be clear, good, and convincing, why should he be shy to have it tried whether they be proof or not? He whose assent goes beyond his evidence owes this excess of his adherence only to prejudice, and does in effect own it when he refuses to hear what is offered against it; declaring thereby that it is not evidence he seeks, but the quiet enjoyment of the opinion he is fond of, with a forward condemnation of all that may stand in opposition to it, unheard and unexamined." (John Locke.)