Albert Einstein was one of the principal founders of the quantum and relativity theories. Until 1925, when the Bose-Einstein statistics was discovered, he made great contributions to the foundations of quantum theory. However, after the discovery of quantum mechanics by Heisenberg and wave mechanics by Schrodinger, with the consequent development of the principles of uncertainty and complementarity, it would seem that Einstein's views completely changed. This is an exploration of Einstein's views on the nature and structure of physics and reality.

At a rather young age I wrote an essay with the pretentious title 'Albert Einstein's Philosophy of Science and Life' for an open essay competition of the International Council of YMCA's. I gave a copy of it to Paul Arthur Schilpp (Editor of Albert Einstein: PhilosopherScientist, Einstein's 70th birthday volume), who was visiting my university to give a lecture; he forwarded it to Einstein. One fine morning I received an aerogram, marked '112 Mercer Street, Princeton, N.J.'; it contained a one-line message: 'Dear Sir: Apart from too unwarranted praise I find your characterization of my convictions and personal traits quite veracious and showing psychological understanding. With kind greetings and wishes, sincerely yours, Albert Einstein [signedl.' (Einstein Archive.) Much more than the prize which I won for my essay, Einstein's letter greatly excited and inspired me for a long time. In the course of time and my later work I met all of my scientific heroes, but Einstein had died on 18 April 1955, before I came to America; however, when I did so about a couple of years later, my first pilgrimage was to his house in Princeton, where Helen Dukas, his loyal secretary, received me and remained very kind and helpful during the following years.