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. (shrink)