1. Plato, Books I–IV (the soul and the city)
2. Aristotle, Book V; Book III
3. Augustine, Book XIX, Chapters 21, 24
4. Aquinas, II-II, Questions 57–61
5. Hobbes, , Part I Chapters 14–15
6. Hume, Book III, Part II; Enquiry Concerning the Principles of Morals, Sections III–IV
7. Kant, ; , Part I
8. Mill, , Chapter V
9. Marx, Critique of the Gotha Program; , Volume I, Chapter 10