have been wanting; and murder, free the world from tyrants and oppressors.  Luxury maintains its thousands, and vanity its ten thousands.  Superstition and arbitrary power contribute to the grandeur of many nations, and the liberties of others are preserved by the perpetual contentions of avarice, knavery, selfishness, and ambition; and thus the worst of vices, and the worst of men, are often compelled, by providence, to serve the most beneficial purposes, contrary to their own malevolent tendencies and inclinations; and thus private vices become public benefits, by the force only of accidental circumstances.  But this impeaches not the truth of the criterion of virtue, before mentioned, the only solid foundation on which any true system of ethics can be built, the only plain, simple, and uniform rule, by which we can pass any judgment on our actions; but by this we may be enabled, not only to determine which are good, and which are evil, but, almost mathematically, to demonstrate the proportion of virtue or vice which belongs to each, by comparing them with the degrees of happiness or misery which they occasion.  But, though the production of happiness is the essence of virtue, it is by no means the end; the great end is the probation of mankind, or the giving them an opportunity of exalting or degrading themselves, in another state, by their behaviour in the present.  And thus, indeed, it answers two most important purposes:  those are, the conservation of our happiness, and the test of our obedience; or, had not such a test seemed necessary to God’s infinite wisdom, and productive of universal good, he would never have permitted the happiness of men, even in this life, to have depended on so precarious a tenure, as their mutual good behaviour to each other.  For it is observable, that he, who best knows our formation, has trusted no one thing of importance to our reason or virtue:  he trusts only to our appetites for the support of the individual, and the continuance of our species; to our vanity, or compassion, for our bounty to others; and to our fears, for the preservation of ourselves; often to our vices, for the support of government, and, sometimes, to our follies, for the preservation of our religion.  But, since some test of our obedience was necessary, nothing, sure, could have been commanded for that end, so fit, and proper, and, at the same time, so useful, as the practice of virtue; nothing could have been so justly rewarded with happiness, as the production of happiness, in conformity to the will of God.  It is this conformity, alone, which adds merit to virtue, and constitutes the essential difference between morality and religion.  Morality obliges men to live honestly and soberly, because such behaviour is most conducive to public happiness, and, consequently, to their own; religion, to pursue the same course, because conformable to the will of their creator.  Morality induces them to embrace virtue, from prudential considerations;