According to Matthew: Lecture 12 of 12: Lecture delivered in Bern, Switzerland on September 12, 1910; from The Collected Works of Rudolf Steiner

These two lecture courses, given just after the beginning of World War I, stand as a kind of unexpected gift. A few months later, once the war became a reality, the possibilities for esoteric work would change and it would become more difficult to do spiritual research. But in the short interval before the true horror of the conflict unfolded, Rudolf Steiner-almost by the way-was able to give these lectures, which lay out in the clearest fashion the path of anthroposophic meditation, and it...