1. Plato, 187–201; 261–264
2. Aristotle, Chapters 1–7; Book I
3. Aquinas, I, Q. 16; Q. 1
4. Descartes, IV
5. Locke, Book IV, Chapters 1–4
6. Hume, Book I, Part III
7. Kant, , Analytic of Principles; , Introduction
8. Hegel, , Doctrine of the Concept, Section on Judgment
9. William James, Principles of Psychology, Chapter XXI