Abstract
Reid argues that Hume’s claim that justice is an artificial virtue is inconsistent with the fact that gratitude is a natural sentiment. This chapter shows that Reid’s argument succeeds only given a philosophy of mind and action that Hume rejects. Among other things, Reid assumes that one can conceive of one of a pair of contradictories only if one can conceive of the other—a claim that Hume denies. So, in the case of justice, the disagreement between Hume and Reid is, at bottom, a disagreement over their respective conceptions of how the human mind works at its most fundamental level.