Thomas Kuhn (1922-1996) was an American philosopher of science. He said that science progresses not by the slow, orderly increase of facts and theories – fact building on fact, theory building on theory – but by one theory overthrowing another.
He called the conquering theory a paradigm and the overthrow a paradigm shift.
Kuhn found this out when he read Copernicus: Copernicus and Ptolemy had the same set of facts, more or less, yet while Ptolemy said the planets went round the earth, Copernicus said they all went round the sun. Copernicus did not “build” on Ptolemy’s theory: he ground it into the dust.
He is not the exception, as it turns out: Dalton did not build on Lavoisier, Darwin did not build on Lamarck and Einstein did not really build on Newton. They each had a new paradigm: a new way of looking at the facts that everyone already knew.
What makes a paradigm powerful is that it not only explains the known facts better, it predicts something surprising that turns out to be true. It also gains followers by opening up new roads into the unknown, just as Copernicus opened up new roads for Galileo, Kepler, Tycho and Newton.
Although the new paradigm has fact and reason on its side, it wins less by persuading the grey hairs and more by winning glory, honour and top positions for the young bloods. In time the grey hairs die off and the young bloods, by middle age, have all the top positions. By this point the paradigm has become the reigning truth. Paradigms win not by sweet reason, but by death and fashion.
Yet after a time new facts start to come in that do not quite fit. The paradigm becomes like a faithful old shoe that has seen its day and is starting to show holes. At first the new facts are not taken seriously, but then more are discovered. It seems like every five years or so someone finds out something new that does not quite fit.
Then a genius comes along with a new way of looking at it all – a new paradigm. He is able to explain the new facts as well as the old.
Then the whole thing starts over again.
Science was not always like this. Greek science certainly was not. Neither are the so-called “soft” sciences like those political and social. Not even computer science.
How to tell philosophy and soft science from true science:
- Theories sound good but cannot be proved to be true or false.
- The existence of different schools of thought.
- In school you read the “great works” of the field.
- There is no overarching theory – just a lot of rules that work.
In political science, for example, you may read Aristotle, but in physics no one thinks to read Galileo, as great as he was. Why? Because physics, as a true science, has progressed far beyond its founders, political science has not.
When a field gets its first paradigm it then becomes a true science.