Turning Points in Spiritual History CW 60-61, by Rudolf Steiner; a selection of six lectures from these collected works. Translated by Walter F. Knox.
A zip file of the entire book.
1. Lecture 1: Zarathustra (Berlin, January 19, 1911)
2. Lecture 2: Hermes (Berlin, February 16, 1911)
3. Lecture 3: Buddha (Berlin, March 2, 1911)
4. Lecture 4: Moses (Berlin, March 9, 1911)
5. Lecture 5: Elijah (Berlin, December 14, 1911)
6. Lecture 6: Christ and the Twentieth Century (Berlin, January 25, 1912)