Capaldi, Nicholas. Hume's Place in Moral Philosophy, New York: Peter Lang, 1989.

From the publisher:

Eighteenth century British moral philosophy focused on three issues: (a) moral apprehension; (b) moral motivation; and (c) the relationship of moral apprehension to moral motivation. Hume resolved these issues by a Copernican revolution in which the basic perspective is that of an engaged and socially responsible agent as opposed to the classic philosophical perspective of the disengaged theoretician. As a consequence he could distinguish clearly the cognitive from the affective elements in moral apprehension, identify the non-moral origins of moral motivation, and account for the growth of the moral perspective through sympathy.

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