[Footnote 25 Decentior equus cujus astricta sunt ilia; sed idem velocior.  Pulcher aspectu sit athieta, cujus lacertos exercitatio expressit; idem certamini paratior.  Nunquam vero species ab utilitate dividitur.  Sed hoc quidem discernere, modici judicii est.  Quinct. lib. 8.  (A horse with narrow flanks looks more comely; It also moves faster.  An athlete whose muscles have been developed by training presents a handsome appearance; he is also better prepared for the contest.  Attractive appearance is invariably associated with efficient functioning.  Yet it takes no outstanding powers of judgement to wake this distinction.)]

The same principle produces, in many instances, our sentiments of morals, as well as those of beauty.  No virtue is more esteemed than justice, and no vice more detested than injustice; nor are there any qualities, which go farther to the fixing the character, either as amiable or odious.  Now justice is a moral virtue, merely because it has that tendency to the good of mankind; and, indeed, is nothing but an artificial invention to that purpose.  The same may be said of allegiance, of the laws of nations, of modesty, and of good-manners.  All these are mere human contrivances for the interest of society.  And since there is a very strong sentiment of morals, which in all nations, and all ages, has attended them, we must allow, that the reflecting on the tendency of characters and mental qualities, is sufficient to give us the sentiments of approbation and blame.  Now as the means to an end can only be agreeable, where the end is agreeable; and as the good of society, where our own interest is not concerned, or that of our friends, pleases only by sympathy:  It follows, that sympathy is the source of the esteem, which we pay to all the artificial virtues.

Thus it appears, that sympathy is a very powerful principle in human nature, that it has a great influence on our taste of beauty, and that it produces our sentiment of morals in all the artificial virtues.  From thence we may presume, that it also gives rise to many of the other virtues; and that qualities acquire our approbation, because of their tendency to the good of mankind.  This presumption must become a certainty, when we find that most of those qualities, which we naturally approve of, have actually that tendency, and render a man a proper member of society:  While the qualities, which we naturally disapprove of, have a contrary tendency, and render any intercourse with the person dangerous or disagreeable.  For having found, that such tendencies have force enough to produce the strongest sentiment of morals, we can never reasonably, in these cases, look for any other cause of approbation or blame; it being an inviolable maxim in philosophy, that where any particular cause is sufficient for an effect, we ought to rest satisfied with it, and ought not to multiply causes without necessity.  We have happily attained experiments in the artificial virtues, where the tendency of qualities to the good of society, is the sole cause of our approbation, without any suspicion of the concurrence of another principle.  From thence we learn the force of that principle.  And where that principle may take place, and the quality approved of is really beneficial to society, a true philosopher will never require any other principle to account for the strongest approbation and esteem.