This leads on to the consideration of the Moral Faculty.
But, in the beginning of Chapter IV., he first rejects one by one these various accounts of the reason of our approbation of moral conduct:--pleasure by sympathy; pleasure through the moral sense; notion of advantage to the agent, or to the approver, and this direct or imagined; tendency to procure honour; conformity to law, to truth, fitness, congruity, &c.; also education, association, &c.

He then asserts a natural and immediate determination in man to approve certain affections and actions consequent on them; or a natural sense of immediate excellence in them, not referred to any other quality perceivable by our other senses, or by reasoning.

It is a sense not dependent on bodily organs, but a settled determination of the soul.

It is a sense, in like manner as, with every one of our powers--voice, designing, motion, reasoning, there is bound up a taste, sense, or relish, discerning and recommending their proper exercise; but superior to all these, because the power of moral action is superior.

It can be trained like any other sense--hearing, harmony, &c .-- so as to be brought to approve finer objects, for instance the general happiness rather than mere motions of pity.