v. 1-2. Philosophy.
v. 3. Philosophy of religion.
v. 4. Religion and society.
v. 5-8. Controversy.
v. 9. Scientific theories.
v. 10-13. Civilization.
v. 14. Development and morals.
v. 15-18. Politics.
v. 19. Literary criticisms.
v. 20. Explanations and index.