Chapter III

As to my required studies, which in the midst of these philosophical interests had naturally to be cramped for time, it was fortunate for me that I had already occupied myself a great deal with differential and integral calculus and with analytical geometry. Because of this I could remain away from many lectures in mathematics without losing my connection. Mathematics was very important for me as the foundation under all my strivings after knowledge. In mathematics there is afforded a system of percepts and concepts which have been reached independently of any external sense impressions. And yet, said I to myself constantly at that time, one carries over these perceptions and concepts into sense-reality and discovers its laws. Through mathematics one learns to understand the world, and yet in order to do this one must first evoke mathematics out of the human mind.