In 1957, Thomas Kuhn, a theoretical physicist turned historian, discovered that everything we thought we knew about science was wrong. Science doesn’t progress by accumulating facts. It progresses through paradigm shifts.

Curated by Business Science Daily — peer-reviewed sources, human-verified. Learn more

About Our Curation Process

Business Science Daily curates academic research in business and management. Each featured study is selected from reputable, peer-reviewed journals, institutional repositories, or working papers (e.g., Elsevier, Sage, NBER, SSRN).

Articles are carefully summarized to ensure clarity and accuracy, with direct citations or links to original sources. Our process emphasizes transparency, academic integrity, and accessibility for a broader audience.

Learn more in our Editorial Standards & AI Policy.

The standard story:

Science progressed by accumulation. Scientists observed nature, formulated hypotheses, tested them against evidence, and gradually built an ever more accurate picture of reality. Wrong ideas were discarded. Right ideas survived. The process was rational, linear, and cumulative. It was, in essence, a story of steady improvement toward truth.

Kuhn discovered that the whole story was wrong.

Not slightly wrong. Not in need of minor correction. Wrong in its fundamental assumptions about what scientists actually do, how they think, and why scientific knowledge changes over time.

What he found, while studying the history of physics, was that scientists do not abandon theories when anomalies appear. They do not test their fundamental assumptions against nature. They do not progress steadily toward truth. Instead, they work within frameworks they rarely question, solve puzzles that those frameworks define, and only abandon those frameworks when an alternative is ready and a sufficient number of colleagues have been persuaded to convert.

The book that emerged from this realization—The Structure of Scientific Revolutions, first published in 1962—does not challenge “How does science justify itself?” but “How does scientific change actually occur?”

It is hard to overstate how thoroughly this reframing transformed the field. Before Kuhn, the philosophy of science was largely concerned with logic, justification, and methodology. After Kuhn, it became concerned with history, sociology, and psychology—with communities and commitments, with persuasion and conversion, with the structures that make scientific knowledge possible. Kuhn did not just offer a new theory of scientific change. He offered a new way of seeing the entire enterprise.

Kuhn’s intellectual journey began not with a grand philosophical ambition but with a specific problem. While preparing to teach a course on physical science for non-scientists, he was forced to engage seriously with historical texts—with Aristotle’s physics, with Ptolemy’s astronomy, with the work of scientists who had been thoroughly wrong by modern standards.

What struck him was not the errors themselves, but the fact that these scientists were not simply confused. They were intelligent, methodical, and deeply committed to understanding nature. Their theories were not arbitrary. They made sense given the assumptions they had inherited and the problems they were trying to solve. The difference between their science and modern science was not a matter of intelligence or method. It was a matter of starting points.

This observation led Kuhn to a troubling question: If science is rational and cumulative, why do entire scientific communities sometimes abandon one framework and adopt another that is incompatible with it? And if progress is a matter of accumulating facts, why do the “facts” themselves seem to change when the framework changes?

The standard philosophical answers were unsatisfactory. Karl Popper had argued that science progresses through conjecture and refutation—bold hypotheses that are subjected to severe tests and discarded when they fail. But Kuhn had found that scientists rarely discard theories, even when they fail tests. They patch them, adjust them, explain away the failures, and carry on.

The logical positivists had argued that scientific theories are verified by evidence, and that science progresses by accumulating verified knowledge. But Kuhn found that the evidence itself is theory-dependent—that what counts as evidence depends on what the scientist already believes. The same observation can be “evidence” for one theory and “anomaly” for another.

What Kuhn needed was a model that could explain why scientists behave the way they actually do, not the way philosophers thought they should. He found it in an unlikely place: the social structure of scientific communities.

Kuhn’s central insight was that science is not primarily an individual endeavor. It is a social enterprise conducted by communities of practitioners who share a common framework. It contains a set of beliefs, values, methods, and exemplary achievements that define what counts as legitimate scientific work.

Kuhn called this framework a paradigm, though he later regretted the term because it was so widely misunderstood. What he meant was something like a shared model. The paradigm is a concrete achievement that provides a template for future research. Newton’s Principia was a paradigm for eighteenth-century physics. Lavoisier’s chemistry was a paradigm for nineteenth-century chemistry. Maxwell’s electromagnetic theory was a paradigm for late nineteenth-century physics.

A paradigm does more than provide a theory. It provides an entire way of doing science. It tells scientists what questions are worth asking, what methods are legitimate, what counts as a solution, and what counts as a puzzle. It defines the field itself.

This is the key to understanding normal science. Normal science is not about discovery or novelty. It is about puzzle-solving. Scientists work within the framework their paradigm provides, trying to solve problems that the paradigm has defined as important and solvable. They are not trying to overturn the paradigm—they are trying to extend and refine it.

This is not a criticism of science. It is a description of how science actually functions. The reason science progresses so quickly is precisely because scientists do not constantly question their fundamental assumptions. They accept them, work within them, and focus their energy on solving concrete problems. The paradigm provides the stability that makes cumulative progress possible.

But this stability comes at a cost. Paradigms also blind scientists. They teach scientists to see what the paradigm expects them to see—and to miss what it does not expect.

Kuhn illustrated this point with an example from the history of astronomy. Before Copernicus, Western astronomers had observed the heavens for centuries without seeing the changes that their theories told them could not occur. The heavens, according to Aristotelian cosmology, were immutable and perfect. New stars did not appear. Existing stars did not vanish.

But the Chinese, who did not share this assumption, had recorded the appearance of new stars and sunspots centuries before they were “discovered” in the West. The difference was not in the quality of observation. It was in what the observers were prepared to see.

This pattern recurs throughout the history of science. Discovery is not simply a matter of looking and seeing. It is a matter of recognizing that something does not fit—that the expected and the observed have come apart.

Take the discovery of oxygen. When Joseph Priestley first produced the gas we now call oxygen, he did not see a new substance. He saw “dephlogisticated air”—a variant of a familiar substance, fitting the existing phlogiston theory. It was only after Lavoisier, working with a different theoretical framework, recognized the gas as something fundamentally new that oxygen entered the scientific world as a distinct entity.

The same gas, the same experiments, the same observations. But what was seen was radically different. And the difference was not a matter of interpretation. It was a matter of perception shaped by paradigm.

Kuhn was careful to avoid claiming that scientists simply invent data. The gas was real. The experiments were real. But what Lavoisier saw when he looked at that gas was not what Priestley saw. Their training, their assumptions, their entire way of viewing chemistry had prepared them to see different things.

This is why Kuhn described paradigm change as a gestalt switch. Just as the duck-rabbit image can be seen as either a duck or a rabbit but not both at once, scientists see the world through their paradigm. When the paradigm changes, the world itself seems to change.

Kuhn’s model of scientific change proceeds through a predictable sequence.

The most controversial aspect of Kuhn’s model is the idea of incommensurability—the claim that successive paradigms cannot be directly compared.

This is not a claim that paradigms are incomparable in any sense. Scientists can and do compare them. They ask: Which paradigm solves more problems? Which is more accurate? Which is simpler? These are meaningful questions.

But they are not decisive. Different scientists weigh these criteria differently. One may value accuracy above all; another may prioritize simplicity. There is no algorithm that dictates the correct choice.

More fundamentally, the very meaning of the terms changes when the paradigm changes. When Einstein replaced Newton, “mass” did not mean the same thing. “Space” and “time” did not mean the same thing. The terms were not simply redefined—they were re-embedded in a different conceptual network.

This makes communication across paradigms difficult. Scientists from different paradigms may use the same words but mean different things. They may look at the same data but see different phenomena. They are, in a sense, living in different worlds.

Kuhn was not claiming that the world itself changes when the paradigm changes. He was not a relativist. But he was claiming that scientists’ experience of the world—what they see, what they notice, what they consider important—changes with the paradigm. And because scientists have no direct access to an unmediated reality, their experience is the world for them.

Kuhn’s model raises a deeper question. If science does not progress toward truth, what does it progress toward?

Kuhn’s answer was both simple and profoundly unsettling: Science progresses by solving problems. It gets better at puzzle-solving. It becomes more articulated, more specialized, more precise. But this progress is not progress toward a pre-existing goal. It is progress away from previous limitations.

This is Kuhn’s evolutionary metaphor. Just as biological evolution does not progress toward a goal but adapts to changing environments, scientific development does not progress toward truth but adapts to the problems that the scientific community defines as important.

The success of science does not depend on its ability to get closer to truth. It depends on its ability to solve puzzles effectively. And the scientific community is structured to maximize puzzle-solving capacity. It is a system designed for problem-solving, not truth-seeking.

This is not a rejection of science. It is a more accurate account of what science actually does. And it is more than sufficient to justify the enormous trust we place in scientific knowledge.