Civil society consists of members obligated to respect each other's rights and, hence, trade with each other as equals. What determines the boundary, rather than the nature, of civil society? For Adam Smith, the boundary consists of humanity itself because it is determined by identification: humans identify with other humans because of common humanness. While Smith's theory can explain the emotions associated with justice (jubilance) and injustice (resentment), it provides a mushy ground for the boundary question: Why not extend the common identity to nonhuman animals? Or why not restrict the boundary to one's own dialect, ethnicity or race? For David Hume, the boundary need not consist of humanity itself because it is determined by self-interest: a European need not respect the property of outsiders such as Native Americans, if the European benefits more by exploiting them than including them in the European society. While Hume's theory can provide a solid ground for the boundary question, it cannot explain the emotions associated with justice. This paper suggests a framework that combines the strengths, and avoids the shortcomings, of Smith's and Hume's theories.