How Science Learned to Examine Its Own Methods

Lavoisier tested ideas by weighing everything in sealed vessels before and after a reaction. That mass accounting let him show that combustion consumes a component of air he named oxygen, and it set aside the phlogiston theory in his 1783 paper Reflections on Phlogiston.

Faraday was a bookbinder's apprentice who became the leading experimentalist at the Royal Institution. His 1831 discovery of electromagnetic induction and his quantitative laws of electrolysis show a method built on repeated, measured laboratory trials rather than on speculation.

Fisher turned experimental method into mathematics. His randomized design assigns subjects to treatment and control by chance so that other differences average out, and his 1925 book Statistical Methods for Research Workers set out the significance threshold researchers still cite. The atlas also records his advocacy of eugenics, a position now widely rejected.

Smith, a metallurgist who served as chief metallurgist on the Manhattan Project, argued that a material's strength and conductivity are governed by structure seen under a microscope and not by its chemical formula alone. His later writing on the history of metallurgy and craft technology asked how makers came to know such things.

Popper proposed falsifiability as the criterion that makes a claim scientific, in his 1934 book Logik der Forschung. He rejected induction as the characteristic method of science and put the possibility of being proved wrong in its place.

Kuhn, trained as a physicist, argued in his 1962 book The Structure of Scientific Revolutions that science alternates between long periods of normal science within a shared paradigm and rare paradigm shifts, rather than accumulating facts smoothly.

Lakatos took up Popper's criterion and reframed it. In his methodology of research programmes, a protected core of assumptions absorbs anomalies, and a programme is progressive if it keeps predicting new facts and degenerating if it only patches itself to survive old ones.

Feyerabend closes the path with the sharpest challenge. His 1975 book Against Method argues from case studies, most centrally Galileo, that no fixed methodological rule survives how major advances actually happened, a position he called epistemological anarchism and which remains contested.