Paradigm Shift

 
Paradigm shift (or revolutionary science) is the term first coined by Thomas Kuhn in his influential book, The Structure of Scientific Revolutions, (1962) to describe a change in basic assumptions within the ruling theory of science.  It is in contrast to his idea of normal science.
  The term paradigm shift, as a change in a fundamental model of events, has since become widely applied to many other realms of human experience as well, even though Kuhn himself restricted the use of the term to the hard sciences. According to Kuhn, "A paradigm is what members of a scientific community, and they alone, share." (The Essential Tension, 1977). Unlike a normal scientist, Kuhn held, "a student in the humanities has constantly before him a number of competing and incommensurable solutions to these problems, solutions that he must ultimately examine for himself." (The Structure of Scientific Revolutions). Once a paradigm shift is complete a scientist cannot, for example, posit the possibility that miasma causes disease or, ether carries light or, evil spirits cause disease.