Einstein's impact on theoretical physics

There occurred in the early years of this century three conceptual revolutions that profoundly changed Man's understanding of the physical universe: the special theory of relativity (in 1905), the general theory of relativity (1915) and quantum mechanics (1925). Einstein personally was responsible for the first two of these revolutions, and influenced and helped to shape the third. But it is not about his work in these conceptual revolutions that he writes about here. Much has been written about that work already. Instead, he discusses, in general terms, Einstein's insights on the structure of theoretical physics and their relevance to the development of physics in the second half of this century. He divides the discussion into four sections which are, of course, very much related