Kuhn defines a paradigm as the generally accepted worldview among the members of the scientific community. This includes the set of theories and standards common to scientists in the field. Change of the paradigm is always heavily resisted, which is why it becomes a revolution.
Of course, we are all naturally reluctant to change our entire worldview. But Kuhn realised that there was more than this at work. As he explains, once a worldview has become a paradigm, meaning a deeply-held and well-structured concept of the world, a new concept that is incompatible with it is automatically rejected. It seems clear it is just obviously wrong. Thus if new research indicates there is a fault in this worldview, this is not seen as refuting the current paradigm but just a mistake by the researcher, however prestigious. Planck’s experience with the discovery of the quantum is a perfect example. The nature of the quantum revealed by experiments was just too weird to be real. So it was endlessly assumed he had just misinterpreted the results.
Catch-22
The problem is this leads to a classic Catch-22. As Kuhn describes:
Once it has achieved the status of a paradigm, a scientific theory is declared invalid only if an alternate candidate is available to take its place. (1962, 77)
But when the alternate candidate is too strange it is not seen as viable, so the original theory remains the accepted worldview by default. Which is what has happened with quantum theory.
This explains the familiar responses to each scientific revolution. Physicist Hermann Weyl noted this exact response to the new physics, saying that physicists and philosophers both continued to:
. . . stick stubbornly to the principles of a mechanistic interpretation of the world after physics had, in its actual structure, already outgrown the latter. They have the same excuse as the land person who for the first time travels on the open sea: he will desperately try to stay in sight of the vanishing coast line, as long as there is no other coast in sight, towards which he steers. (Scholz, 2004, 3)
There has been no new coast in sight. Nothing recognisable could be found in the paradoxes of the new physics. Results of experiments seem to be dependent on experience, which is an oxymoron in the physicalism of the current worldview.
As the requirement of a viable alternative has not been met, the current worldview has remained stuck while the new physics carries on without a proper explanation. So the meaning of the new physics has lain by the wayside, a pearl in an oyster unopened.
Normal Science
Kuhn came to realise that all modern day science, without exception, is conducted within the context of the existing theories. He termed this ‘normal science’, meaning working within the community in order to refine the structure of the existing paradigm. Therefore, he observed, major shifts in the current paradigm never happen as part of the progressive development of scientific research, the normal science. And as he describes, although anomalies are inevitably discovered, these are swept under the carpet as acceptable levels of error. Or, if they are too potentially intrusive, simply ignored.
No part of the aim of normal science is to call forth new sorts of phenomenon; indeed those that will not fit the box are often not seen at all. (1962, 24)
Scientific revolutions are always breakdowns of the ordinary business of normal science. Kuhn describes these huge changes as scientific revolutions. Each one is a major ‘paradigm shift’, a sea change deep and wide in our comprehension of the world. The current paradigm shift may be the biggest of all time. Not only is the world very different to what we take for granted but so too are we ourselves. Which would explain why it has been so incomprehensible for a hundred years. There is a double whammy of paradigm shifts.
On to the next section The Personal World.