This is a classic book on the history of freedom of thought, covering ancient Greece and Rome, the Middle Ages, and the Renaissance. In addition, this early monograph deals with the Reformation, followed by the seventeenth, eighteenth, and nineteenth centuries.
- Reason Free (Greece and Rome)
- Reason in Prison (The Middle Ages)
- Prospect of Deliverance (The renaissance and the reformation)
- Religious Toleration
- The Growth of Rationalism (seventeenth and eighteenth centuries)
- The Progress of Rationalism (nineteenth century)
- The Justification of Liberty of Thought