"As God," says Blackstone, "when he created matter, and endowed it with a principle of mobility, established certain rules for the perpetual direction of that motion, so when he created man, and endued him with free will to conduct himself in all parts of life, he laid down certain immutable laws of human nature whereby that free will is in some degree regulated and restrained, and gave him also the faculty of reason to discover the purport of those laws." This law of nature being coeval with mankind, and dictated by God himself, is of course superior in obligation to any other. It is binding all over the globe, in all countries and at all times: no human laws are of any validity if contrary to this; and such of them as are valid, derive all their force and all their authority, mediately or immediately, from this original. Human laws originate in the wisdom of man, and are designed to regulate their behavior to one another, and are enforced by human authority and worldly sanctions. The fear of punishment and revenge are not strong enough to control the lusts and passions of men. The true idea and comprehension of the majesty and mercy of the law is infused by the spirit of philosophy. IV. "The existence of states," says Montesquieu, "is like that of man, and the first have the right to make war for their proper preservation; the latter have the right to kill in the case of natural defence. In the case of natural defence I have the right to kill, since my life is my own, as the life of him who attacks me belongs to himself. * * * From the right of war follows that of conquest, which is the consequence: it ought then to follow the spirit. * * * It is clear when the conquest is made, the conqueror has no longer the right to kill, since he is no longer in the position of natural defence, or for his proper preservation. "That which has made them think thus (right to kill), is that they have believed that the conqueror had the right to destroy society, whence they have concluded that they had that to destroy the men who composed it, which is a false consequence extracted from a false principle. Because the society should perish, it does not follow that the men who form it ought also to perish. Society is a union of men, and not men: the citizen can perish and the man remain. From the right to kill in conquest, politics have derived the right to enslave; but the consequence is as badly founded as the principle." There are certain rules that arise from the principle of self-preservation, and form what Wolff calls "the voluntary law of nations." "Hence it follows that all nations have a right to repel by force what openly violates the law of the society which nature has established among them, or that directly attacks the welfare and safety of that society. At the same time care must be taken not to extend this law to the prejudice of the liberty of nations." V.