The Challenge of the Times, a collection of 6 lectures by Rudolf Steiner. (From CW 186 which in the original German contains 12 lectures)
For your convenience, below is a zip file of this entire set of lectures. It does require that you have an unzipping utility of some kind on your computer. For you mac people this is built in.
The Entire Book The Challenge of the Times
1. East and West from a Spiritual Point of View (November 29, 1918)
2. The Present from the Viewpoint of the Present (November 30, 1918)
3. The Mechanistic, Eugenic and Hygienic Aspects of the Future (December 1, 1918)
4. Social and Antisocial Instincts (December 6, 1918)
5. Specters of the Old Testament in the Nationalism of the Present (December 7, 1918)
6. The Innate Capacities of the Nations of the World (December 8, 1918)