text: "The Structure of Scientific Revolutions, popularized the idea of “paradigm shift” in science, the way perception of the physical universe can be turned upside down by abrupt changes in world view...."  I know Dr. Kingwell is far better informed than I about philosophy, but I'm not sure he's doing Thomas Kuhn's book justice here, which I read more than once when I was younger and which actually to some extent informs my own world view. 
  
   Kuhn said that paradigms shift when, after a long period of time anomalies pile up about things that are considered fact (the earth is flat, or the center of the solary system, etc.).   Finally so many anomalies accumulate, that the paradigm shifts.  The shift is not actually abrupt, but can appear so.  
  
  This kind of thing applies to social affairs and politics as well.  Revolutions when they break out may same sudden and shocking, but the build up may have been going on for a long long time.  Suddenly the world becomes  a secular place.  And so on.