Abstract: In Hume and Smith's treatise on the origin of justice, there exists a logical chain from utility to aesthetic feeling, happiness, virtue and finally the justice, and passion plays a more important role than rationality. Hume pays more attention on justice as mutual advantage, while Smith emphasizes justice as impartiality, in fact, these two kinds of justice are complementary and can be unified. To realize justice through ways such as conventions in society, these two great thinkers especially Hume bring to light some key ideas, which can be regarded as the precursors to Nash equilibrium and incentive in modern game theory and institution design.