Medicine and the Philosophy of Rene Descartes; Cogito ergo sum

Rene Descartes at work Credit: Public Domain, Wikipedia Commons


The French philosopher and mathematician Rene Descartes (1596-1650) gave a high priority to medicine and dedicated a great deal of his life to medical studies. Nevertheless, his relation to medicine has always been debated. A number of recent works have contributed to reassessing the earlier critique which nearly wrote him out from medical history. The recent biographical dismissal of a number of earlier allegations and the recent interpretations of the medical contents of his collected writings ought to result in Descartes’ reinstatement in medical history.


Painting of Rene Descartes by Frans Hals – Credit: After Frans Hals – Andre Hatala [e.a.] (1997) De eeuw van Rembrandt, Bruxelles: Credit communal de Belgique, ISBN 2-908388-32-4., Public Domain; Wikipedia Commons


His novel anti-Aristotelian methodology had a crucial influence on the medicine of the subsequent decades. Also, his early defense of Harvey’s theory of blood circulation had great influence. Especially his thoughts about a mechanical physiology by means of which the functions of the body could be explained without involvement of “occult faculties“ influenced that time. His empirical mistakes, including the central role which he ascribed to the corpus pineale, are offset by his brilliant thoughts about the function and importance of the brain. Although he did not make any really new empirical discoveries within medicine, he advanced a number of concrete ideas which later lead to actual discoveries such as visual accommodation, the reflex concept and the reciprocal innervations of antagonistic muscles. Descartes’ psychosomatic view of the importance of the interplay between sensations, “the passions of the soul“, and the free will in the preservation of health shows in addition that his fundamental soul-body dualism was far more nuanced than is often claimed. Descartes developed a system of dualism which distinguishes between the “mind,“ whose essence is thinking, and “matter,“ whose essence is extended into space; with more flexibility for definition. This dualism influenced his mechanical interpretation of nature and therefore of the human body. He believed that the laws of physics and mathematics explain human physiology.


According to One Hundred Books Famous in MedicineDe homine, “is the first work in the history of science and medicine to construct a unified system of human physiology that presents man as a purely material and mechanical being: man as machine de terre.“ This concept helped free the study of physiology from the constraints of religion and culture. De homine is an important early textbook of physiology, but empirically flawed because Descartes’ practical knowledge of his subject was inadequate. With extraordinary courage, Descartes refused to accept the authority of previous philosophers. He frequently set his views apart from those of his predecessors. In the opening section of the Passions of the Soul, a treatise on the early modern version of what are now commonly called emotions, Descartes goes so far as to assert that he will write on this topic “as if no one had written on these matters before“. His best known philosophical statement is “Cogito ergo sum“ The thrilling nature of this stance is not only that Descartes separated the study of man (philosophy and medicine) from religious dogma, but he created new pathways of medical and scientific inquiry, deviating from nearly two thousand years of unquestioned adherence to the medical knowledge of Hippocrates (360 BCE) and Galen (129 CE  200 CE).


Human ideas die hard. The history of science and medicine gives clear proof of this. Ideas change fast in the 21st Century, therefore, it’s hard to believe that the approach to medicine barely changed over approximately 2,000 years and that the teachings of Hippocrates and Galen lasted right up to the 17th Century. At this point, the great genius of Rene Descartes asserted, “No, I am different.“ His creativity literally changed the history of human thought. Descartes originally planned to publish De homine in 1633, but hearing of Galileo’s condemnation by the Church, he became concerned for his own safety and refused to have it printed. Consequently, the first edition of this work appeared 12 years after Descartes’ death. The French edition, L’homme, also includes la formation du foetus which explains reproductive generation in physiological terms. Sources:; Wikipedia;



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