Albert Schweitzer, Albert Schweitzer: An Anthology, ed. Charles R. Joy. Boston: Beacon, 1947 contains the following note on Schweitzer's first course of lectures:
November 1934. Gifford Lectures at Edinburgh, in which he endeavored to trace the progress of human thought from the great thinkers of India, China, Greece, and Persia. The chapter upon the evolution of Indian thought grew to such an extent that he decided to publish it as a separate book. It was issued under the German title of Die Weltanschauung der indischen Denker by Beck at Munich in 1934; under the French title Les Grands Penseurs d'Inde by Payot at Paris in 1936; and under the English title Indian Thought and Its Development by Hodder and Stoughton at London in 1936. The same year it was published by Henry Holt and Company in New York. (p. 328)
Another note (1937–39), which seems to be a reference to his second course of lectures, indicates that "he ... planned to publish separately the chapters on the Chinese thinkers in whom he had become deeply interested." (p. 328) This volume was, however, never published.