Scientific Method

The scientific method — the cluster of practices by which claims about the natural world are tested, verified, and organized into systematic knowledge — has no single inventor and no fixed definition. In the history of medicine, the concept has served both as a genuine methodological standard and as a rhetorical weapon, invoked by nearly every medical school and tradition to distinguish itself from its rivals. The Hippocratics claimed it against temple medicine; the iatrochemists claimed it against Galenism; the vitalists claimed it against mechanism; the laboratory scientists claimed it against clinical empiricism. Thomas Kuhn’s work demonstrated that what scientists actually do bears little resemblance to the textbook model of hypothesis, experiment, and conclusion — and that the relationship between method and discovery is far more contingent than the standard narrative suggests.

The Textbook Model and Its Limits

Science textbooks present a cumulative, developmental model of science: each generation builds on the discoveries of the last, and scientific knowledge grows by steady accretion (Kuhn, 1962). Kuhn argued that this model fundamentally misrepresents how science actually develops. Historians studying past theories — Aristotelian dynamics, phlogistic chemistry, caloric thermodynamics — find them neither less scientific nor more idiosyncratic than current theories; they were coherent responses to the evidence available at the time (Kuhn, 1962).

Methodological directives alone cannot dictate a unique scientific conclusion. Prior experience, accident, and individual makeup are always formative ingredients in the beliefs embraced by a scientific community (Kuhn, 1962). Scientific fact and theory are not categorically separable (Kuhn, 1962). Normal science, far from being a neutral search for truth, suppresses fundamental novelties because they are subversive of its basic commitments (Kuhn, 1962).

Induction, Controls, and Critical Judgment in Medicine

King’s analysis of Boerhaave’s methodology provides a detailed case study of how scientific method works — and fails — in medical practice. Boerhaave defined scientific knowledge as grounded in two sources: facts and experiments (observable, sense-verifiable data) and reasoning founded upon them (King, 1958). His criterion for a sound inductive inference was that it be “so evident as to compel every reasonable Person, skilled in his Profession, to allow it for true” (King, 1958).

Yet Boerhaave’s practice often fell short of his principles. He effectively demolished Schuyl’s claimed experimental proof that bile and pancreatic juice effervesce on mixing by demonstrating adequate positive and negative controls — showing what good experimental method looked like when applied rigorously (King, 1958). But he himself committed the epistemological error of adopting plausible hypotheses without seeking positive confirmatory evidence or adequate controls (King, 1958). His theory that alcohol hardens body fibres was fundamentally flawed because it neglected the differences between in vivo and in vitro conditions (King, 1958).

King’s general principle: mere absence of contrary evidence does not bestow any cogency on a given assertion; positive evidence and adequate controls are both required (King, 1958). A physician may be an excellent scientist with inadequate techniques if he remains sufficiently critical, and may be a poor scientist with excellent information if he lacks critical judgment (King, 1958). Boerhaave’s great deficiency as a scientist was doctrinal conservatism — he paid lip service to inductive method and decried hypotheses, but lacked critical acumen (King, 1958).

King praises John Pringle for a rarer virtue: the willingness to suspend judgment rather than formulate speculative hypotheses — an attitude King identifies as the true modern investigative spirit (King, 1958).

Paradigms and Normal Science

Kuhn’s framework reconceived the relationship between method and discovery. Paradigms gain their status not by being exhaustive but by being more successful than competitors in solving a few acute problems; their initial success is a promise, not a completed programme (Kuhn, 1962). Normal science is “an attempt to force nature into the preformed and relatively inflexible box that the paradigm supplies” (Kuhn, 1962).

Laws like Boyle’s Law and Coulomb’s Law were not found by pure induction but emerged through paradigm articulation — history offers no support for an excessively Baconian method (Kuhn, 1962). The scientific revolutions that do transform paradigms — those associated with Copernicus, Newton, Lavoisier, and Einstein — require not merely new data but the community’s rejection of one time-honored theory in favour of another incompatible with it (Kuhn, 1962).

The Gap Between Laboratory and Publication

Geison’s study of Pasteur’s private laboratory notebooks revealed a systematic discrepancy between what Pasteur did in the laboratory and what he reported in publications. This gap is a general feature of science, not unique to Pasteur (Geison, 1995). Peter Medawar observed that scientific papers “actively misrepresent the reasoning that goes into the work they describe” (Geison, 1995).

Pasteur’s science was shaped not only by experimental evidence but by personal ambition and political, philosophical, and religious concerns (Geison, 1995). His campaign against spontaneous generation, for instance, was shaped by concerns specific to Second Empire France (Geison, 1995). His notebooks reveal he encountered experimental results that could have supported spontaneous generation but dismissed them as experimental errors (Geison, 1995). Geison argues the debate was not decisively settled by experiment alone; Pasteur “won” in part because the political and religious climate favoured his position (Geison, 1995).

Hippocratic Rationalism

Temkin argues that the rationalism of Hippocratic medicine — its rejection of supernatural causes of disease — constituted a necessary but insufficient condition for science (Temkin, 1977). The Hippocratics established that diseases have natural causes and follow predictable courses, but they did not develop the experimental controls, quantitative methods, or institutional structures that later came to define scientific practice. The gap between Hippocratic clinical observation and modern experimental method is not a failure of the ancients but a measure of how much institutional and conceptual infrastructure the “scientific method” requires.

See Also

• Experimental Medicine
• Epistemology
• Clinical Observation
• Isaac Newton
• Antoine Lavoisier
• Louis Pasteur
• Scientific Revolution

Sources

All claims cite evidence cards from:

• King, L.S. (1958). The Medical World of the Eighteenth Century. Chicago: University of Chicago Press. [Source ID: king-medicalworld-1958]
• Kuhn, T.S. (1962). The Structure of Scientific Revolutions. Chicago: University of Chicago Press. [Source ID: kuhn-scientificrevolutions-1962]
• Geison, G.L. (1995). The Private Science of Louis Pasteur. Princeton: Princeton University Press. [Source ID: geison-private-science-pasteur-1995]
• Temkin, O. (1977). The Double Face of Janus. Baltimore: Johns Hopkins. [Source ID: temkin-doublefacejanus-1977]

Editorial Notes

Gaps the encyclopaedia compiler flagged for future evidence work, collected from inline markers in the body and frontmatter.

Sources