Fifty years ago, Thomas Kuhn, then a professor at the University of California, Berkeley, released a thin volume entitled The Structure of Scientific Revolutions. Kuhn challenged the traditional view of science as an accumulation of objective facts toward an ever more truthful understanding of nature. Instead, he argued, what scientists discover depends to a large extent on the sorts of questions they ask, which in turn depend in part on scientists’ philosophical commitments. Sometimes, the dominant scientific way of looking at the world becomes obviously riddled with problems; this can provoke radical and irreversible scientific revolutions that Kuhn dubbed “paradigm shifts” — introducing a term that has been much used and abused. Paradigm shifts interrupt the linear progression of knowledge by changing how scientists view the world, the questions they ask of it, and the tools they use to understand it. Since scientists’ worldview after a paradigm shift is so radically different from the one that came before, the two cannot be compared according to a mutual conception of reality. Kuhn concluded that the path of science through these revolutions is not necessarily toward truth but merely away from previous error. . .
The argument of Structure is not especially complicated. Kuhn held that the historical process of science is divided into three stages: a “normal” stage, followed by “crisis” and then “revolutionary” stages. The normal stage is characterized by a strong agreement among scientists on what is and is not scientific practice. In this stage, scientists largely agree on what are the questions that need answers. Indeed, only problems that are recognized as potentially having solutions are considered scientific. So it is in the normal stage that we see science progress not toward better questions but better answers. The beginning of this period is usually marked by a solution that serves as an example, a paradigm, for further research . . .
A crisis occurs when an existing theory involves so many unsolved puzzles, or “anomalies,” that its explanatory ability becomes questionable. Scientists begin to consider entirely new ways of examining the data, and there is a lack of consensus on which questions are important scientifically. Problems that had previously been left to other, non-scientific fields may now come into view as potentially scientific.
Eventually, a new exemplary solution emerges. This new solution will be “incommensurable” — another key term in Kuhn’s thesis — with the former paradigm, meaning not only that the two paradigms are mutually conflicting, but that they are asking different questions, and to some extent speaking different scientific languages. Such a revolution inaugurates a new period of normal science.
Hmmm, any of this sound familiar?