1. Plato, Books VI–VII (the Divided Line, the Sun, the Cave); ;
2. Aristotle, Books I–II; Book I
3. Augustine, ; Book X
4. Aquinas, I, Questions 84–88
5. Montaigne, , "Apology for Raymond Sebond"
6. Descartes, , I–IV
7. Locke, , Books I–II
8. Hume, , Sections II–V, VII
9. Kant, , Introduction, Transcendental Aesthetic, Transcendental Analytic (selections)
10. Hegel, , Preface and Introduction
11. William James, , Lectures II, VI