- A Comparative View of Religions
- Chips from a German Workshop, Volume 1: Essays on the Science of Religion
- Colloquium heptaplomeres de rerum sublimium arcanis abditis
- London Lectures of 1907
- Modern Saints and Seers
- Ten Great Religions: An Essay in Comparative Theology
- The Oriental Religions in Roman Paganism
- The Ruins; Or, Meditation on the Revolutions of Empires and the Law of Nature
- The Sympathy of Religions