Philosophy of Science: How Scientific Knowledge Works

What Makes a Theory Scientific

Science is the most successful method for obtaining reliable knowledge about nature that humanity has ever invented. But what exactly makes a theory “scientific” rather than just “a clever idea”?

Karl Popper proposed the criterion of falsifiability: a theory is scientific if it is possible to indicate an observation that would disprove it. Newtonian mechanics is scientific (experiments can disprove it, and some have—favoring relativistic mechanics). The general theory of relativity is scientific (its predictions are testable). Astrology is not scientific (any configuration of stars can be retrofitted to any event).

An important consequence: science advances not by accumulating confirmations, but by falsifications. A thousand confirming cases do not prove a theory—one refuting observation (provided the experiment is conducted properly) falsifies it.

Thomas Kuhn: Paradigms and Scientific Revolutions

Thomas Kuhn (“The Structure of Scientific Revolutions,” 1962) attacked the image of science as a linear progression of knowledge. He introduced the concept of the paradigm: a combination of exemplars, theories, methods, and standards accepted by the scientific community that defines “normal science.”

Within a paradigm, scientists solve “puzzles”—problems for which the paradigm prescribes a method. Anomalies (data that do not fit the paradigm) are initially ignored or explained ad hoc. When too many anomalies accumulate, a crisis sets in. The crisis is resolved by a scientific revolution: the old paradigm is replaced by a new one (Ptolemaic astronomy → Copernican; phlogiston chemistry → oxygen chemistry; Newtonian physics → relativistic + quantum).

Kuhn introduced the concept of incommensurability of paradigms: scientists of different paradigms literally see different things, use different language, and solve different problems. Revolutions are not merely the addition of new knowledge, but a change in the entire “grid” of categories.

Lakatos: Research Programmes

Imre Lakatos reconciled Popper and Kuhn. His concept of the research programme: a hard core (irrefutable basic assumptions) is surrounded by a protective belt of auxiliary hypotheses, which absorb the blows of falsifications. A progressive programme predicts new facts; a degenerative one only explains after the fact.

A programme continues as long as it is progressive. When it stagnates and a competing programme surpasses it in predictive power, a replacement occurs.

Paul Feyerabend: Anarchism in Methodology

Paul Feyerabend (“Against Method,” 1975)—a radical position: there is no single scientific method. Historically, great breakthroughs often violated established methodological rules. Galileo did not simply use a different method—he used rhetoric, propaganda, appeal to public opinion against Aristotelian science. “Anything goes” is a provocative slogan against methodological monism.

Feyerabend does not deny science—he denies its monopoly on knowledge. Traditional practices, folk medicine, alternative theories deserve consideration, not automatic rejection.

Reductionism, Holism, and Levels of Explanation

Can psychology be “reduced” to neurobiology, neurobiology to biochemistry, biochemistry to physics? Reductionists believe: in principle, yes. Holists: no, at each level, emergent properties arise that cannot be reduced to the lower level. Consciousness is not just “a very large number of neural connections.”

In scientific practice, both approaches are productive. Biochemistry has reduced many diseases to molecular defects. Ecology and systems biology study emergent properties of ecosystems that cannot be described by the properties of individual organisms.

Reflection Question: In your professional field—what “paradigm” (set of accepted assumptions, methods, standards) currently dominates? Are there signs of accumulating anomalies indicating a possible paradigm shift?