affection tends to the happiness of another does not hinder its
tending to one's own happiness too. That others enjoy the benefit
of the air and the light of the sun does not hinder but that these
are as much one's own private advantage now as they would be if we
had the property of them exclusive of all others. So a pursuit
which tends to promote the good of another, yet may have as great
tendency to promote private interest, as a pursuit which does not
tend to the good of another at all, or which is mischievous to him.
All particular affections whatever, resentment, benevolence, love of
arts, equally lead to a course of action for their own
gratification; i.e., the gratification of ourselves; and the
gratification of each gives delight: so far, then, it is manifest
they have all the same respect to private interest. Now take into
consideration, further, concerning these three pursuits, that the
end of the first is the harm, of the second, the good of another, of
the last, somewhat indifferent; and is there any necessity that
these additional considerations should alter the respect, which we
before saw these three pursuits had to private interest, or render
any one of them less conducive to it, than any other? Thus one
man's affection is to honour as his end; in order to obtain which he
thinks no pains too great. Suppose another, with such a singularity
of mind, as to have the same affection to public good as his end,
which he endeavours with the same labour to obtain. In case of
success, surely the man of benevolence hath as great enjoyment as
the man of ambition; they both equally having the end their
affections, in the same degree, tended to; but in case of
disappointment, the benevolent man has clearly the advantage; since
endeavouring to do good, considered as a virtuous pursuit, is
gratified by its own consciousness, i.e., is in a degree its own
reward.