
Editor's Note: We are republishing this article by Paul Dirac from the May 1963 issue of Scientific American, as it might be of interest to listeners to the June 24, 2010, and June 25, 2010 Science Talk podcasts, featuring award-winning writer and physicist Graham Farmelo discussing The Strangest Man, his biography of the Nobel Prize-winning British theoretical physicist.
In this article I should like to discuss the development of general physical theory: how it developed in the past and how one may expect it to develop in the future. One can look on this continual development as a process of evolution, a process that has been going on for several centuries.