 The time, it is hoped, is gone by when any defense would be necessary of the liberty of the press as one of the securities against corrupt or tyrannical government. No argument, we may suppose, can now be needed against permitting a legislature or an executive not identified an interest with the people to prescribe opinions to them and determine what doctrines or what arguments they shall be allowed to hear. This aspect of the question, besides, has been so often and so triumphantly enforced by preceding writers that it need not be specifically insisted on in this place. Though the law of England on the subject of the press is as servile to this day as it was in the time of the tutors, there is little danger of it being actually put in force against political discussion, except during some temporary panic when fear of insurrection drives ministers and judges from their propriety, and speaking generally it is not in constitutional countries to be apprehended that the government, whether completely responsible to the people or not, will often attempt to control the expression of opinion, except when in doing so it makes itself the organ of the general intolerance of the public. Let us suppose therefore that the government is entirely at one with the people and never thinks of exerting any power of coercion unless in agreement with what it conceives to be their voice. But I deny the right of the people to exercise such coercion, either by themselves or by their government. The power itself is illegitimate. The best government has no more title to it than the worst. It is as noxious or more noxious when exerted in accordance with public opinion than when in opposition to it. If all mankind minus one were of one opinion and only one person were of the contrary opinion, mankind would be no more justified in silencing that one person than he if he had the power would be justified in silencing mankind. Were an opinion a personal possession of no value except to the owner? If to be obstructed in the enjoyment of it were simply a private injury, it would make some difference whether the injury was inflicted only on a few persons or on many, but the peculiar evil of silencing the expression of an opinion is that it is robbing the human race, posterity, as well as the existing generation, those who dissent from the opinion still more than those who hold it. If the opinion is right, they are deprived of the opportunity of exchanging error for truth. If wrong, they lose what is almost as great a benefit, the clearer perception and livelier impression of truth produced by its collision with error. I do not pretend that the most unlimited use of the freedom of enunciating all possible opinions would put an end to the evils of religious or philosophical sectarianism. Every truth which men of narrow capacity are in earnest about is sure to be asserted, inculcated, and in many ways even acted on as if no other truth existed in the world, or at all events none that could limit or qualify the first. I acknowledge that the tendency of all opinions to become sectarian is not cured by the freest discussion, but is often heightened and exacerbated thereby. The truth which ought to have been seen, but was not seen, being rejected all the more violently because proclaimed by persons regarded as opponents. But it is not on the impassioned partisan, it is on the calmer and more disinterested bystander that the collision of opinions works its salutary effect. Not the violent conflict between parts of the truth, but the quiet suppression of half of it is the formidable evil. There is always hope when people are forced to listen to both sides. It is when they attend only to the one that errors harden into prejudices, and truth itself ceases to have the effect of truth by being exaggerated into falsehood. And since there are few mental attributes more rare than that judicial faculty which can sit in intelligent judgment between two sides of a question, of which only one is represented by an advocate before it, truth has no chance, but in proportion as every side of it, every opinion which embodies any fraction of the truth not only finds advocates, but is so advocated as to be listened to. We have now recognized the necessity to the mental well-being of mankind, and on which all other well-being depends, of freedom of opinion, and freedom of the expression of opinion on four distinct grounds which we will now briefly recapitulate. First, if any opinion is compelled to silence, that opinion may, for ought we can certainly know, be true. To deny this is to assume our own infallibility. Secondly, though the silenced opinion be an error, it may and very commonly does contain a portion of the truth. And since the general or prevailing opinion on any subject is rarely or never the whole truth, it is only by the collision of adverse opinions that the remainder of the truth has any chance of being supplied. Thirdly, even if the received opinion be not only true but the whole truth, unless it is suffered to be and actually is vigorously and earnestly contested, it will by most of those who receive it be held in the manner of a prejudice, with little comprehension or feeling of its rational grounds. And not only this, but fourthly, the meaning of the doctrine itself will be in danger of being lost or enfeebled and deprived of its vital effect on the character and conduct. The dogma becomes a mere formal profession inethicaceous for good, but combering the ground and preventing the growth of any real and heartfelt conviction from reason or personal experience. Before quitting the subject of freedom of opinion, it is fit to take some notice of those who say that the free expression of all opinions should be permitted on condition that the manner be temperate and do not pass the bounds of fair discussion. Much might be said on the impossibility of fixing where these supposed bounds are to be placed, for if the test be offense to those whose opinion is attacked, I think experience testifies that this offense is given whenever the attack is telling and powerful, and that every opponent who pushes them hard, and whom they find it difficult to answer, appears to them if he show any strong feeling on the subject an intemperate opponent. But this, though an important consideration and a practical point of view, merges in a more fundamental objection. Undoubtedly, the manner of asserting an opinion, even though it be a true one, may be very objectionable and may justly incur severe censure, but the principal offenses of the kind are such as it is mostly impossible, unless by accidental self-betrayal, to bring home to conviction. The gravest of them is to argue sophistically, to suppress facts or arguments, to misstate the elements of the case, or misrepresent the opposite opinion. But all this, even to the most aggravated degree, is so continually done in perfect good faith by persons who are not considered, and in many other respects may not deserve to be considered ignorant or incompetent, that it is rarely possible, on adequate grounds conscientiously, to stamp the misrepresentation as morally culpable, and still less could law presume to interfere with this kind of controversial misconduct, with regards to what is commonly meant by intemperate discussion, namely invective, sarcasm, personality and the like. The denunciation of these weapons would deserve more sympathy, if it were ever proposed to interdict them equally to both sides. But it is only desired to restrain the employment of them against the prevailing opinion, against the unprovaling they may not only be used with general disapproval, but will be likely to obtain for him who uses them the praise of honest zeal and righteous indignation. Yet whatever mischief arises from their use is greatest when they are employed against the comparatively defenseless, and whatever unfair advantage can be derived by any opinion from this mode of asserting it, accrues almost exclusively to received opinions. The worst defense of this kind, which can be committed by a polemic, is to stigmatize those who hold the contrary opinion as bad and immoral men. To Calumny of this sort, those who hold any unpopular opinion are peculiarly exposed, because they are in general few and uninfluential, and nobody but themselves feels much interested in seeing just as done them. But this weapon is, from the nature of the case, denied to those who attack a prevailing opinion. They can neither use it with safety to themselves, nor, if they could, would it do anything but recoil on their own cause? In general, opinions contrary to those commonly received can only obtain a hearing by studied moderation of language, and the most cautious avoidance of unnecessary offense, from which they hardly ever deviate, even in a slight degree without losing ground. While unmeasured vituperation employed on the side of the prevailing opinion really does deter people from professing contrary opinions, and from listening to those who profess them. For the interest, therefore, of truth and justice, it is far more important to restrain this employment of vituperative language than the other. And, for example, if it were necessary to choose, there would be much more need to discourage offensive attacks on infidelity than on religion. It is, however, obvious that law and authority have no business with restraining either, while opinion ought, in every instance, to determine its verdict by the circumstances of the individual case, condemning everyone on whichever side of the argument he places himself, in whose mode of advocacy, either want of candor, or malignity, bigotry, or intolerance, of feeling manifest themselves, but not inferring these vices from the side which a person takes, though would be the contrary side of the question to our own, and giving merited honor to everyone, whatever opinion he may hold, who has calmness to see, and honesty to state what his opponents and their opinions really are, exaggerating nothing to their discredit, keeping nothing back which tells, or can be supposed to tell, in their favor. This is the real morality of public discussion, and, if often violated, I am happy to think that there are many controversialists who, to a great extent, observe it, and a still greater number who conscientiously strive towards it. Thanks for watching.