Secondly, though the silenced opinion be an error, it may, and very commonly does, contain a portion of 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 becoming a mere formal profession, inefficacious for good, but cumbering 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 offence to those whose opinion is attacked, I think experience testifies that this offence 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 shows any strong feeling on the subject, an intemperate opponent. But this, though an important consideration in 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 offences 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 regard 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