This is a very famous book. It was written in 1962, then revised twice by the author, and then reissued on its 50th anniversary with a very long foreword (the author died in 1996).
The book describes how science moves forward. According to the author, science exists in “paradigms,” which are ways of thinking about and framing a domain of problems. (Apparently, this was the book that popularized the word “paradigm.”)
We “solve puzzles” within paradigms, until we start to encounter problems which bump up against and challenge the paradigm, in which we’re working. When that happens, we have a “paradigm shift” which changes everything, and future people work within the new paradigm.
For example, people used to think that the stars rotated around the Earth. We solved puzzles based on that core belief. Then, one day, Galileo found problems with this, and he theorized that the Earth – and lots of other things – resolved around the sun. This became the new paradigm.
So, science doesn’t always move forward smoothly. It can “lurch” suddenly.
The Wikipedia page for the book summarizes this as five phases:
Phase 1 – It exists only once and is the pre-paradigm phase, in which there is no consensus on any particular theory.
Phase 2 – Normal science begins, in which puzzles are solved within the context of the dominant paradigm. As long as there is consensus within the discipline, normal science continues.
Phase 3 – If the paradigm proves chronically unable to account for anomalies, the community enters a crisis period. Crises are often resolved within the context of normal science.
Phase 4 – Paradigm shift, or scientific revolution, is the phase in which the underlying assumptions of the field are reexamined and a new paradigm is established.
Phase 5 – Post-revolution, the new paradigm’s dominance is established and so scientists return to normal science, solving puzzles within the new paradigm.
This is very interesting, but, honestly, the book is a very, very tough read. I got pretty much all of my understanding from companion reading and summaries.
The book was written during the heyday of physics, particular nuclear research. So most of these examples are from that discipline, and they’re complicated. I can’t say that I understood most of it.
I had the 50th anniversary edition, which means I had a long introduction from Ian Hacking who is a noted “philosopher of science” (he just recently died, in May 2023).
And that’s the interesting part of the book: it’s not about science, as much as it’s about the flow of scientific discovery. It’s about a philosophy or meta-understanding of how science works.
The core point is valid and critical: we are confined by ways of thinking, and eventually we question them until we finally up-end them completely. That is a very true understanding for almost every field of human endeavor, and I’m better for formalizing it in my own head.