In this episode I look at an important aspect of the history of science, namely the occurrence of scientific revolutions. I start with a brief history of the Scientific Revolution (1543-1687), discussing the contributions of Copernicus, Kepler, Galileo and Newton. Their achievements suggest some useful criteria, which help to understand what a scientific revolution is. I look at Kuhn's work on scientific revolutions but, for the reasons explained, give preference to an alternative model (the chain-of-reasoning model). I proceed to test this model with respect to Darwinism and Freudianism.

Darwin passes the test: he was the author of a true scientific revolution. Although Freud claimed that he had completed the Copernican revolution, he does not pass the test.

The work of all three of them - Copernicus, Darwin and Freud - had important consequences for the way humans look at the world. The consequence of the Copernican revolution was that humans could no longer see themselves as the centre of the universe. The consequence of the Darwinian revolution was that humans could no longer see themselves as the crown of creation. Freud did not instigate a scientific revolution but his work had a massive impact on Western culture. He 'created' homo psychologicus - the psychological human.

Literature:

The classic studies of scientific revolutions are Th. S. Kuhn, The Structure of Scientific Revolutions (1970) and I. B. Cohen, Revolution in Science (1985). This episode is based on my book Copernicus, Darwin & Freud (2009). Further literature on shepherd.com.