BERNARD, CLAUDE
(1813–1878)

Claude Bernard, French physiologist, was born in Saint-Julien (Rhône). He received his M.D. in 1843 and became a professor at the Sorbonne in 1852, taking the new chair in physiology in 1854. The following year he was appointed professor of experimental medicine at the Collège de France and in 1868 became professor of general physiology at the Museum of Natural History in Paris. He was elected a member of the Academy of Sciences in 1854 and of the Académie Française in 1868; in 1869 he became a senator.

Bernard early gave up any idea of clinical practice in favor of experimental physiology. He made a number of important contributions in this field (on the chemistry of digestion, the production of sugar in animals, the nervous system, poisons, and anesthetics), many of which were awarded scientific prizes. After a period of ill health, while not ceasing laboratory work, he turned to more general and programmatic questions of scientific method and published, in particular, his famous Introduction à l'étude de la médecine expérimentale (Paris, 1865; translated by H. C. Green as An Introduction to the Study of Experimental Medicine, New York, 1927).

In the Introduction, Bernard based his conclusions as much as possible on his own scientific experiences, since he believed that proper procedure cannot be legislated for scientists from without but must be developed from the nature and needs of science itself. He distinguished the mature experimental method from empiricism, which is merely its first step. Bernard identified crude empiricism, which observes and experiments at random, not only with his own teacher, François Magendie, but also, mistakenly, with Francis Bacon, regarding himself rather in the tradition of Descartes, despite the fact that he insisted on constant laboratory experimentation and criticism and had a low opinion of the application of mathematics to biological problems. His hostility to the use of statistical methods in biology derived from the one article of faith he regarded as necessary to any scientist: belief in the operation of a determinism without exceptions, such that a set of conditions (a cause) will invariably produce the same phenomenon (an effect). This determinism he called an absolute principle, in contrast to theories and hypotheses, which are always provisional and subject to revision or abandonment because of the discovery of incompatible facts. But theories and hypotheses, the products of human reason, are on the other hand the necessary guides for rational experimentation.

Bernard saw no difference in principle between scientific method as applied to living beings and to inorganic matter, although results were more difficult to achieve in physiology because of the far greater complexity of the phenomena. He believed in a fundamental unity among all forms of life, the higher forms being distinguished by their greater independence of the external environment and a correspondingly greater dependence on their "internal environment" (above all, the blood). He also held that the phenomena taking place in living beings are ultimately reducible to physicochemical processes. Efforts to enlist Bernard in the cause of vitalism are wide of the mark. Equally mistaken is the attempt to affix a positivist label. He strenuously advocated scientific doubt and self-criticism, and was opposed to all philosophical systems, including the positivist, while not denying the usefulness of the work of philosophers in their own sphere. Bernard's critical method was closer to twentieth-century methods based on the principle of falsifiability, used by Karl Popper and others, than to those of many of his contemporaries.

See also Bacon, Francis; Descartes, René; Empiricism; Popper, Karl Raimund; Positivism; Scientific Method; Vitalism.

Bibliography

Bernard's general works also include La science expérimentale (Paris: J. B. Baillière, 1878) and Principes de médecine expérimentale (Paris: Presses universitaires de France, 1947).

For works on Bernard, consult J. M. D. Olmsted and E. H. Olmsted, Claude Bernard and the Experimental Method in Medicine (New York: H. Schuman, 1952); Robert Clarke, Claude Bernard et la médecine expérimentale (Paris, 1961); and Paul Foulquié, Claude Bernard (Paris: Éditions de l'école, 1954).

W. M. Simon (1967)