Paradigm

In order to justify his claim that there is no neutral set of observations or experiments that could help scientists determine which paradigm is true, Kuhn argues that the Gestalt experiments show how it is possible to think of a scientist as seeing the world very differently after a change of paradigm. Examples of scientists s eeing different things after a change of paradigm include the following: The earth was seen as the center of the universe, then as a planet orbiting one of millions of stars. Light was seen first as a particle, then as a wave, and finally as a photon. Uranus was first seen as a star, then as a comet, then finally as a planet when William Herschel (1738–1822) "discovered" it. Dephlogisticated air was later seen as oxygen. Stones restrained from falling to their natural place were later seen as the repetitive motion of a pendulum. Kuhn argues that the revolutionary changes described in these examples are not simply changes in the name of something: Phlogiston is not anti-oxygen, the pendulum is not a falling stone, and so forth. Scientists working in different paradigms collect different data and work on different problems. Something that formerly needed to be explained may be seen as natural under a new paradigm, and what seemed natural before may now seem to need an explanation. Therefore "the historian of science may be tempted to exclaim that when paradigms change, the world itself changes with them" (1996, p. 111).

Although he occasionally said contradictory things on this issue in Structure, Kuhn later insisted that the scientists working under different paradigms really do live in different worlds. Paradigms cannot be said to be different interpretations of a single objective world because "interpretation" only happens within a paradigm. We do not see the world as it really is but rather have to learn how to see, guided by the paradigm. Without a paradigm, there would be no science at all; rather there would only be confusion, a point that Kuhn makes with his reference to the experiments of Jerome S. Bruner and Leo Postman with anomalous playing cards and of George M. Stratton with inverted vision. Kuhn introduced the term incommensurability to describe the difficulty of comparing one paradigm to another. There is no way to test a paradigm as a whole or to compare the predictions that derive from paradigms against one another, as scientists do when they test theories. Kuhn argues that in cases where the same word is used in two different paradigms or when it seems that the same phenomenon can be described in both, the words in fact have different meanings in each paradigm and the phenomenon is not the same.

Revolutions have been covered up by textbooks, whose job it is to teach current science, not to teach history of science. Words are applied anachronistically, and the development of science is made to look linear and cumulative. As a historian, Kuhn discovered that there are radically different ways of doing science. He sought a way of expressing his discovery and of explaining the immersion into a historical text that is required for understanding. The concept of a paradigm is central to Kuhn's expression of his discovery and to his attempt to correct philosophical misrepresentations of science.