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543 particular, and having found that natural, as well as civil justice, derives its origin from human conventions, we shall quickly perceive, how fruitless it is to resolve the one into the other, and seek, in the laws of nature, a stronger foundation for our political duties than interest, and human conventions; while these laws themselves are built on the very same foundation. On which ever side we turn this subject, we shall find, that these two kinds of duty are exactly on the same footing, and have the same source both of their first invention and moral obligation. They are contriv'd to remedy like inconveniences, and acquire their moral sanction in the same manner, from their remedying those inconveniences. These are two points, which we shall endeavour to prove as distinctly as possible.

We have already shewn, that men invented the three fundamental laws of nature, when they observ'd the necessity of society to their mutual subsistence, and found, that 'twas impossible to maintain any correspondence together, without some restraint on their natural appetites. The same self-love, therefore, which renders men so incommodious to each other, taking a new and more convenient direction, produces the rules of justice, and is the first motive of their observance. But when men have observ'd, that tho' the rules of justice be sufficient to maintain any society, yet 'tis impossible for them, of themselves, to observe those rules, in large and polish'd societies; they establish government, as a new invention to attain their ends, and preserve the old, or procure new advantages, by a more strict execution of justice. So far, therefore, our civil duties are connected with our natural, that the former are invented chiefly for the sake of the latter; and that the principal object of government is to constrain men to observe the laws of nature. In this respect, however, that law of nature, concerning the performance of promises, is only compriz'd along with the rest; and its exact observance is to be consider'd as an effect of the institution of government, and not the obedience to government as an effect of the obligation, of a promise. Tho' the object of our