It may now be ask'd in general, concerning this pain or pleasure, that distinguishes moral good and evil, From what principles 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 produc'd 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 contain'd in the compleatest 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 everything is carry'd 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.