Thomas Kuhn
1922 CE – 1996 CE · Contemporary Era
“The historian of science who shattered the myth that science progresses by steady accumulation. His concept of 'paradigm shifts': upheavals where one scientific worldview replaces another: became widely influential, reshaping how we understand not just science but knowledge itself.”
Biography
An American physicist turned philosopher of science at Harvard, UC Berkeley, Princeton, and MIT. His 1962 book The Structure of Scientific Revolutions is one of the most cited academic works of all time and introduced the phrase 'paradigm shift' into everyday language. He challenged the positivist view that science follows a single, rational method of incremental progress.
Major Works
Key Arguments
Click “Philosophy 101” to read the full exploration of each argument.
Paradigm Shifts and the Structure of Scientific Revolutions
Kuhn argued that science does not progress by the steady accumulation of facts. Instead, it alternates between long periods of 'normal science', puzzle-solving within an accepted framework or 'paradigm', and dramatic 'paradigm shifts' where the entire framework is overthrown and replaced. The Copernican revolution, Einstein's relativity, and quantum mechanics were not simply additions to existing knowledge; they required scientists to see the world in entirely different ways. During a paradigm shift, the old and new frameworks are 'incommensurable', they literally cannot be compared on a common scale because the very meanings of key terms change.
Why it matters: Reshaped philosophy of science, sociology, and the humanities. The concept of paradigm shifts has been applied far beyond science, to business, politics, culture, and technology. Kuhn forced a reckoning with the idea that scientific progress is not purely rational but involves social, psychological, and historical forces.
Incommensurability of Paradigms
Kuhn's most bold and controversial thesis was that successive paradigms are 'incommensurable', they cannot be fully translated into each other's terms. A Newtonian physicist and an Einsteinian physicist using the word 'mass' are not disagreeing about the same concept; they mean different things by the term. This means there is no neutral, paradigm-independent language in which to compare rival theories. Scientists working in different paradigms are, in an important sense, living in different worlds.
Why it matters: Challenged the basic assumption that science converges on a single objective truth. Critics like Karl Popper accused Kuhn of relativism, while supporters saw him as honestly describing how science actually works. The debate over incommensurability remains central to philosophy of science.
Normal Science and the Role of Anomalies
Most science, Kuhn argued, is 'normal science', the workaday activity of solving puzzles defined by the reigning paradigm. Scientists are not trying to overthrow the paradigm; they are extending and refining it. But inevitably, anomalies accumulate, observations and experiments that the paradigm cannot explain. At first these are ignored or explained away. Only when anomalies become severe enough to create a 'crisis' does the scientific community become open to revolutionary change. Even then, the shift is not instantaneous, older scientists often never accept the new paradigm, and as Max Planck observed, science advances 'one funeral at a time.'
Why it matters: Provided an influential description of how scientific communities actually function. Kuhn argued that resistance to new ideas is not mere stubbornness but a structural feature of how knowledge-making works, normal science requires commitment to a paradigm to be productive, but that same commitment creates inertia against change.
Lasting Influence
Argued that science progresses through paradigm shifts, not steady accumulation, changing how we understand the nature of scientific knowledge.
Your Reading Path
The Companion Guide
Seven eras of philosophy in one volume — reading lists, key terms, journal prompts · $19.99