"Normal science does not aim at novelties of fact or theory and, when successful, finds none."
Thomas Kuhn (1922 – 1996) was an American historian and philosopher of science who spent most of his career at Harvard. His most important work The Structure of Scientific Revolutions (1962), which fused history and philosophy of science in a then-unique way, with myriad consequences for all investigations into the nature and meaning of science.
In Structure Kuhn argued that scienc...e progresses in alternating periods of Normal and Revolutionary Science. Normal Science is characterized by broad acceptance of a Paradigm, or master-theory, which scientists believe constitutes the best available explanation of the evidence. The work of scientists in such a period is to apply the paradigm to their observations, in a process Kuhn calls Puzzle-Solving. Over time scientists discover an increasing number of puzzles that resist solution, and confidence in the paradigm will begin to falter. Eventually a Scientific Revolution will introduce a new paradigm which will displace the old and usher in a new period of normal science.
As a general rule the new paradigm will incorporate the insights of the old, but this is not always the case. The adoption of a new paradigm could result in less compelling descriptions of phenomena, or Kuhn Loss. Paradigms exercise a decisive influence on the perception, interpretation, and communication of both evidence and theories. For this reason, comparison across differing paradigms is impossible – their contents are Incommeasurable.
Kuhn wrote in response to the Vienna Circle, whose ahistorical thinking left their theories vulnerable to the kind of argument offered in Structure. It is one of the most important philisophical works of the 20th century, and has been immensely influential in both the humanities and the sciences. Before its publication the tendency was to view science as the rational activity par excellence.
Afterwards it became impossible to ignore the role of social processes, and the principle question became to what extent, rather than whether, these processes influence scientific outcomes. In general philosophers of science have tended to uphold the rationality of the sciences, whereas a new sociological approach has tended to downplay it. The result has been a contentious and long-running debate across numerous academic disciplines, as to exactly how the sciences ought to be regarded.
Part of a Series on Science, Technology, and Society (VIII of XX)