The Structure of Scientific Revolutions

Thomas Kuhn Important philosopher of science His most famous work: The Structure of Scientific Revolutions Came up with the concepts of normal science and paradigm shifts

Scientific Paradigm Scientists have certain background practices and beliefs that they follow These includes rules for method and commonly accepted theories There is always a common paradigm that most scientists work within but they change Example: Ptolemaic astronomy vs. Copernican astronomy

Normal science Nearly all scientists working within the “mainstream” scientific paradigm are doing what’s called “normal science” Normal science is what is taught at schools and universities In other words, normal science is science that “makes” the same assumptions as mainstream science

Paradigm shifts Every so often science “shifts” paradigms A scientists or a small group of scientists will make a discovery that doesn’t fit within the assumptions of normal science These findings are tested If the scientific community accepts them, and accepts that they “overrule” normal science, there is a paradigm shift

What was normal science becomes antiquated There is then a “new” normal science within the new paradigm New scientists will be taught the new ways of doing things

Who breaks through paradigms? Young scientists getting their career started with less to lose by proposing risky theories Old scientists with less to lose because they are about to croak Brilliant scientists with the brains and evidence (and often the reputation) to make people consider their new theories

Examples of paradigm shifts From Aristotelian physics to classical (Newtonian) physics From Ptolemaic astronomy to Copernican astronomy From classical Newtonian physics to Einsteinean physics

Those who shift paradigms Galileo, Copernicus, Kepler: brave, gutsy physicists with the evidence on their side Newton: brilliant physicist with the evidence on his side Einstein: brilliant physicist with the evidence on his side

What do they have in common? When they first proposed their theories, they were ridiculed if not persecuted (and often accused of doing pseudoscience) More and more people read their theories and paid attention They were eventually canonized, and to go against them was taboo, even if they didn’t get it totally right

Knowledge Issues/questions If scientists have background practices and assumptions too, does that mean there is no such thing as scientific truth? Are there really radical paradigm shifts, or is most scientific change gradual? Does Kuhn’s views of science have application to other areas of knowledge? (For example, is it right to consider the move from Freudian to modern psychology a Kuhnian paradigm shift?) How useful of a metaphor is the paradigm for thinking about our lives? (“I went through a paradigm shift when I got a job in the real world.”)