ABSTRACT
Book III opens with a theme which follows easily from Hume’s discussion of the passions. He takes as his object of attack the view that morality is derived from reason. 1
Those who affirm that virtue is nothing but a conformity to reason, that there are eternal fitnesses and unfitnesses of things, which are the same to every rational being that considers them; that the immutable measures of right and wrong impose an obligation, not only on human creatures but also on the Deity himself: All these systems concur in the opinion, that morality, like truth, is discern’d merely by ideas, and by their juxta-position and comparison. In order, therefore, to judge of these systems, we need only consider, whether it be possible, from reason alone to distinguish betwixt moral good and evil, or whether there must concur some other principle to enable us to make that distinction. 2
