Jaspers, Karl (1883-1969), was a leading German existentialist philosopher. He held that philosophy is not a set of doctrines, but an activity through which individuals can become aware of the nature of their own existence. Jaspers wrote many books about the great philosophers of the past. However, he was not primarily interested in the philosophers' conclusions, because he held that in philosophy all content and all conclusions are unimportant. Jaspers urged the study of other philosophers as a way to disturb and stimulate us so profoundly that we would be compelled to engage in the activity of philosophizing. See Existentialism.