A Treatise of Human Nature - Volume 3

our ideas or impressions we distinguish between vice and virtue, and pronounce an action blameworthy or praiseworthy? This will immediately cut off all loose discourses and declamations, and reduce us to something precise and exact on the present subject.

PART I.

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 who 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 agree in the opinion that morality, like truth, is discerned merely by ideas, and by their juxtaposition and comparison. In order, therefore, to judge these systems, we need only consider whether it is possible, from reason alone, to distinguish between moral good and evil, or whether other principles must concur to enable us to make that distinction.

IF morality naturally had no influence on human passions and actions, it would be in vain to take such pains to instill it; and nothing would be more fruitless than that multitude of rules and precepts with which all moralists abound. Philosophy is commonly