T 3.2.2.24

After men have found by experience, that their selfishness |and confin'd generosity, acting at their liberty, totally incapacitate them for society; and at the same time have observ'd, that society is necessary to the satisfaction of those very passions, they are naturally induc'd to lay themselves under the restraint of such rules, as may render their commerce more safe and commodious. To the imposition then, and observance of these rules, both in general, and in every particular instance, they are at first induc'dmov'd only by a regard to interest; and this motive, on the first formation of society, is sufficiently strong and forcible. But when society has become numerous, and has encreas'd to a tribe or nation, this interest is more remote; nor do men so readily perceive, that disorder and confusion follow upon every breach of these rules, as in a more narrow and contracted society. But tho' in our own actions we may frequently lose sight of that interest, which we have in maintaining order, and may follow a lesser and more present interest, we never fail to observe the prejudice we receive, either mediately or immediately, from the injustice of others; as not being in that case either blinded by passion, or byass'd by any contrary temptation. Nay when the injustice is so distant from us, as no way to affect our interest, it still displeases us; because we consider it as prejudicial to human society, and pernicious to every one that approaches the person guilty of it. We partake of their uneasiness by sympathy; and as every thing, which gives uneasiness in human actions, upon the general survey, is call'd Vice, and whatever produces satisfaction, in the same manner, is denominated Virtue; this is the reason why the sense of moral good and evil follows upon justice and injustice. And tho' this sense, in the present case, be deriv'd only from contemplating the actions of others, yet we fail not to extend it even to our own actions. The general rule reaches beyond those instances, from which it arose; while at the same time we naturally sympathize with others in the sentiments they entertain of us. Thus self-interest is the original motive to the establishment of justice: but a sympathy |with public interest is the source of the moral approbation, which attends that virtue. This latter principle of sympathy is too weak to controul our passions, but has sufficient force to influence our taste, and give us the sentiments of approbation or blame.