Section I: Of the Questions which ought to be examined in a Theory of Moral Sentiments If we examine the most celebrated and remarkable of the different theories which have been given concerning the nature and origin of our moral sentiments, we shall find that almost all of them coincide with some part or other of that which I have been endeavouring to give an account of; and that if every thing which has already been said be fully considered, we shall be at no loss to explain what was the view or aspect of nature which led each particular author to form his particular system. From some one or other of those principles which I have been endeavouring to unfold, every system of morality that ever had any reputation in the world has, perhaps, ultimately been derived. As they are all of them, in this respect, founded upon natural principles, they are all of them in some measure in the right. But as many of them are derived from a partial and imperfect view of nature, there are many of them too in some respects in the wrong.
In treating of the principles of morals there are two questions to be considered. First, wherein does virtue consist? Or what is the tone of temper, and tenour of conduct, which constitutes the excellent and praise-worthy character, the character which is the natural object of esteem, honour, and approbation? And, secondly, by what power or faculty in the mind is it, that this character, whatever it be, is recommended to us? Or in other words, how and by what means does it come to pass, that the mind prefers one tenour of conduct to another, denominates the one right and the other wrong; considers the one as the object of approbation, honour, and reward, and the other of blame, censure, and punishment?
We examine the first question when we consider whether virtue consists in benevolence, as Dr Hutcheson imagines; or in acting suitably to the different relations we stand in, as Dr Clarke supposes; or in the wise and prudent pursuit of our own real and solid happiness, as has been the opinion of others.
We examine the second question, when we consider, whether the virtuous character, whatever it consists in, be recommended to us by self-love, which makes us perceive that this character, both in ourselves and others, tends most to promote our own private interest; or by reason, which points out to us the difference between one character and another, in the same manner as it does that between truth and falsehood; or by a peculiar power of perception, called a moral sense, which this virtuous character gratifies and pleases, as the contrary disgusts and displeases it; or last of all, by some other principle in human nature, such as a modification of sympathy, or the like.
I shall begin with considering the systems which have been formed concerning the first of these questions, and shall proceed afterwards to examine those concerning the second.