Pierre-Jean Cabanis

Cabanis, Pierre-Jean (1757–1808)

Cabanis believed in the possibility of a ‘science of man’, having its basis in medicine. He tried to show how a materialist conception of the human organism can throw light on our mental and moral life. The properties of living matter were derived from physical laws, but had their own peculiarities. In particular, the property of sensibility (being able to have sensations) and the property of motility (involving the experience of effort and of resistance to it) were the keys to understanding human nature.

Though the thrust of Cabanis’ thought is materialistic, his emphasis on medical science distinguishes him both from the mechanistic tradition as represented by La Mettrie, and from the intellectualist tradition represented by Condillac, in which sensations are taken as given mental items, from which the rest of our mental life is constructed by operations of reasoning or association.

1 Life and works

Cabanis was born in Cosnac in the Limousin. He was registered as a medical doctor in Reims in 1784, after seven years’ study in Paris (during which he had already become a protégé of Mme d’Helvétius, encountering Condillac, Condorcet, Benjamin Franklin, Mirabeau and Theodore Roosevelt in her circle). His radical ideas about the reform of medical practice and education would perhaps have made it difficult for him to be accepted by the medical establishment in Paris at the time. However, he did not make his profession as a doctor (though he treated Mirabeau, and published an account of Mirabeau’s illness and death in 1791). Instead, he put his medical knowledge to political and philosophical use. In 1790, he wrote his Observations sur les hôpitaux (Observations on Hospitals) and this led to public office, including membership of the Commission on Hospitals, under the revolutionary régime. He also took an active interest in educational reform.

Like many members of the salon of Mme d’Helvétius at Auteuil, he withdrew from the public scene during the Reign of Terror, for fear of Robespierre. When he re-emerged, it was to stand for the ideals of reason, the perfectibility of the human species, and freedom. He was made Professor of Hygiene, and Professor of Clinical Medicine at the École de Médecine in Paris, and was elected to the Conseil des Cinq-Cents. On the creation of the Institut de France, he became a member of the short-lived ‘Class of Moral and Political Sciences’, where he delivered the series of memoirs which formed his major work, published in 1802: the Rapports du physique et du moral de l’homme (Relations between the Physical and the Mental in Man). He became a senator in 1797, having supported Bonaparte’s coup d’état of 18 Brumaire. However, he overtly opposed Bonaparte’s growing authoritarianism. He belonged to a group of thinkers devoted to idéologie (the ‘science of ideas’). The word was coined by Destutt de Tracy, a leader of that group, which included figures like Condorcet, Laplace and Lavoisier. But Napoleon soon adopted a repressive approach, and the appellation idéologue came to connote intellectual, social and political subversiveness. In about 1807, Cabanis seems to have composed a letter to Fauriel on first causes, in which he made concessions to the religious revival. The letter was published only in 1824, but we may surmise that Cabanis felt the need to seek some accommodation with the Imperial authority, as did other thinkers in the first decade of nineteenth-century Paris.

2 Thought

Cabanis was among those figures of the Enlightenment and post-Enlightenment period who believed passionately in the possibility and importance of a ‘science of man’. The systematic understanding of brute matter which the mechanical philosophy had made possible should be matched in our understanding of the human species. This was not, of course, a new ideal, but what was distinctive in Cabanis’ pursuit of it was his view that this understanding must be rooted in medical science, broadly conceived.

The memoirs which make up his Relations between the Physical and the Mental in Man, though materialist in cast, are concerned primarily with the special properties of living matter, especially in the human species. However, this was not necessarily a vitalist position. Indeed, Cabanis places his study of these properties in the context of a much more general principle, that of attraction, illustrated by gravity in physics, and by ‘affinities’ in chemistry and biology. Nevertheless, it is clear that he gives a certain autonomy to our understanding of living matter. Cabanis began this work by insisting that the moral and medical sciences must deal with human beings as whole creatures. Like Descartes, he insisted on the union of mind and body, but unlike Descartes he was no dualist, adopting a broadly materialist approach, which gave a central role to sensation. The property of being able to have sensations, though peculiar to living matter, was derived from more general physical laws, and could give rise to unconscious as well as conscious psychological phenomena. The physiological underlayers of sensation could be seen at work in differences between the sexes, and other mental differences between people arising from their inherited physical constitution in interaction with environmental factors. Cabanis had no account of how life arose, and thought that we should not speculate about causes whose existence could not (as he thought) be experimentally verified, but he believed that one source of the development of life was the inheritance of acquired characteristics. This led him to argue for selective breeding of humans.

This summary of a diverse and wide-ranging set of memoirs is very incomplete, but it shows how Cabanis held a position which already had a substantial background, for instance, in the work of Boerhaave, Stahl, Bonnet, Haller, La Mettrie and others, authors whose importance he fully acknowledged. But these thinkers were divided. Could our understanding of living matter be a simple derivation from our understanding of matter in general? Or were there special types of explanation at play in the case of living matter? Some maintained that a single principle was at work in living matter, others, like Haller, made a radical distinction between a physical property of ‘irritability’ responsible for lower and unconscious functions not involving sensation, and a sensitive property which was responsible for sensation and other mental functions which were derived from it.

Cabanis, as we have already indicated, preferred a monistic position. Indeed, he was particularly known for his claim that just as the stomach digests food, so the brain is a device for digesting sense impressions: he said that it carried out ‘the secretion of thought’. Some of his contemporaries, such as Maine de Biran, strongly rejected this claim. Nevertheless, Cabanis’ systematic treatment of the physiological underlayer of our mental existence, with its exploration of internal factors such as sex, health, bodily chemistry, inherited dispositions, habituation, as well as external ones such as nutrition and climate, marked a distinct break with the intellectualist analyses of eighteenth-century sensualism, typified by Condillac. Like Bonnet, whom he admired, Cabanis could be seen as attempting to ‘naturalize’ sensualism. Relations is a wide-ranging work which also gives an important role to language, envisages ‘transformism’ (a precursor of evolutionary theory) and emphasizes the importance of motility: Cabanis claims that the consciousness of self requires the experience of effort, and of resistance to it (this view influenced Maine de Biran, who made it a main element in his own philosophy).

There is significant disagreement about how to read Cabanis’ position. Some, including some modern commentators, have regarded him simply as a materialist. Others have viewed his work as endorsing some version of vitalism. The situation is further complicated by the posthumously published letter to Fauriel on first causes (Lettre à Fauriel sur les causes premières, 1824). Although called a ‘letter’, this is in fact a book-length opus. Some commentators have gone so far as to ignore it; others have viewed it as a recantation of Cabanis’ former robust materialism; others again consider that it raises questions of method which were Cabanis’ concern all along. On the latter interpretation, we should point out how, all along, Cabanis abjured the search for ‘essences’, ‘occult powers’ or ‘first causes’, a commonplace at the time. We should be empiricists, neither postulating nor speculating about the unobservable, but confining ourselves to what can be established by observation. The letter to Fauriel, however, distinguishes between what can be ‘demonstrated’ in this way, and what can be argued for only by calculating probabilities. The latter may, according to this ‘letter’, re-admit a religious world-view as something with a certain probability, even though it cannot be demonstrated by scientific methods. In the background were Châteaubriand’s Le Génie du Christianisme (1802), and the influence of the Illuminati, and the many other factors which were bringing the end of the Enlightenment (see Illuminati).

Whether or not we regard this posthumously published ‘letter’ as a recantation, Cabanis’ principal work had a substantial and fruitful impact on the early development of psychology and its connections with physiology, being reprinted several times up to the middle of the nineteenth century.