ABSTRACT
Throughout the early period of my life almost all my serious working time was devoted to mathematics. I supposed in those days that I was more interested in the application of mathematics to the explanation of natural phenomena than in pure mathematics for its own sake. This emphasis changed with time, and it was the purest of pure mathematics that finally claimed me. This change had various causes but one of the most important was a desire to refute Kant, whose theory of space and time as a priori intuitions seemed to me horrid. All this, however, belongs to a later date, and so do the revolutionary discoveries and theories which distinguished the physics of our century from the physics of Newton and his successors.
