This statement has the great merit of being, at least, perfectly clear and definite. In some particular cases, the principle may be difficult of application; but in the principle itself, as defined in this passage, there is not the slightest uncertainty or indistinctness. The author is very careful, however, to except from its operation all persons who are not in the maturity of their faculties, as well as all those backward nations who are not capable of being improved by free and equal discussion. The condition of society in which alone this liberal maxim will be safe and appropriate, must be that of a people so far elevated and enlightened, that persuasion and conviction are the most powerful means of improvement. Wherever is to be found an advanced civilization, with all the complex moral and social relations which grow out of it, there the necessity for physical force will be found to have declined. Public opinion will have acquired great authority, if not absolute control; and the rights of individuals will require, for their protection against the overpowering weight of the social combination, all those safeguards against possible tyranny, which can only be afforded by the general acceptance of the liberal principle just quoted. The social authority must be educated and restrained by its own willing recognition of individual rights. As the power most likely to be abused for purposes of oppression is that of opinion and custom, too often operating silently and insidiously, the corrective is only to be applied by the establishment of a counteracting spiritual authority, in the bosom of society itself, at all times ready to utter its mandate and to proclaim the inviolable sanctity of individual liberty, within the limits fixed by enlightened reason and conscience. In the earlier stages of civilization, or in societies of more simple and primitive character, individual development has not reached the point which either requires such principles or admits of their application. The merely physical life of such people can hardly give rise to these questions: political power and actual force necessarily occupy the place of those subtle and all-pervading moral and social influences which prevail in the subsequent stages of progress. As men become more enlightened, they become also more capable of self-control, and are consequently entitled to greater liberty of action. Sooner or later, the necessity for conceding it to the utmost limit of the principle stated, will be fully acknowledged.