The good qualities of an enemy are hurtful to us, but may, still command our esteem and respect. 'Tis only when a character is considered in general, without reference to our particular interest, that it causes such a feeling or sentiment as denominates it morally good or evil. 'Tis true, those sentiments from interest and morals are apt to be confounded, and naturally run into one another. It seldom happens that we do not think an enemy vicious, and can distinguish betwixt his opposition to our interest and real villany or baseness. But this hinders not but that the sentiments are in themselves distinct; and a man of temper and judgment may preserve himself from these illusions. In like manner, though 'tis certain a musical voice is nothing but one that naturally gives a _particular_ kind of pleasure; yet 'tis difficult for a man to be sensible that the voice of an enemy is agreeable, or to allow it to be musical. But a person of a fine ear, who has the command of himself, can separate these feelings, and give praise to what deserves it. _Secondly_, we may call to remembrance the preceding system of the passions, in order to remark a still more considerable difference among our pains and pleasures. Pride and humility, love and hatred, are excited, when there is any thing presented to us that both bears a relation to the object of the passion, and produces a separate sensation, related to the sensation of the passion. Now, virtue and vice are attended with these circumstances. They must necessarily be placed either in ourselves or others, and excite either pleasure or uneasiness; and therefore must give rise to one of these four passions, which clearly distinguishes them from the pleasure and pain arising from inanimate objects, that often bear no relation to us; and this is, perhaps, the most considerable effect that virtue and vice have upon the human mind. It may now be asked, _in general_ concerning this pain or pleasure that distinguishes moral good and evil, _From what principle is it derived, and whence does it arise in the human mind_? To this I reply, _first_, that 'tis absurd to imagine that, in every particular instance, these sentiments are produced by an _original_ quality and _primary_ constitution. For as the number of our duties is in a manner infinite, 'tis impossible that our original instincts should extend to each of them, and from our very first infancy impress on the human mind all that multitude of precepts which are contained in the completest system of ethics. Such a method of proceeding is not conformable to the usual maxims by which nature is conducted, where a few principles produce all that variety we observe in the universe, and every thing is carried on in the easiest and most simple manner. 'Tis necessary, therefore, to abridge these primary impulses, and find some more general principles upon which all our notions of morals are founded.