De homine figuris.

Leyden: Petrus Leffen and Franciscus Moyardus, 1662.

First edition of “the first European textbook of physiology” (Norman). “Descartes considered the human body a material machine, directed by a rational soul located in the pineal body. This book was the first attempt to cover the whole field of ‘animal physiology’” (Garrison-Morton). “Without Descartes, the seventeenth-century mechanization of physiological conceptions would have been inconceivable” (DSB). “The work was based upon Descartes's concept of ‘l’homme machine’, an automaton constructed by God to approximate real men as closely as possible; by means of this literary device, Descartes was able to avoid the restrictions and encumbrances of traditional physiology and theology, and to explain all physical motions, except for deliberately wilful, rational, or self-conscious behaviour, in purely mechanical terms. The work is particularly noteworthy for containing ‘the first descriptive statement of involuntary action which bears a recognisable resemblance to the modern concept of reflex action’ (Fearing, Reflex Action (1964), p. 26) … Descartes wrote De homine as a physiological appendix to Discourse de la Methode (1637), but suppressed it after the condemnation of Galileo in 1633, fearing that his mechanic mechanistic view of the human body might be considered heretical. It was first published in this Latin translation by Florentius Schuyl (1619-69), with the original French version appearing two years later” (Norman). “Physiology grew and developed as an integral part of his philosophy. Although grounded at fundamental points in transmitted anatomical knowledge and actually performed dissection procedures, it sprang up largely independently of prior physiological developments and depended instead on the articulation of the Cartesian dualist ontology, was entangled with the vagaries of metaphysical theory, and deliberately put into practice Descartes’ precepts on scientific method … Throughout his active philosophical life, physiology formed one of Descartes’ most central and, sometimes, most plaguing concerns” (DSB). Guibert mentions two states of the title page: one with the imprint as in our copy and a woodcut device showing an angel under a laurel tree (motto ‘isigne maxime laurus’); and another with the names of the publishers reversed, and a device of a phoenix rising from the flames (motto ‘ex morte immortalia’). He does not establish any priority of issue.

The Treatise on Man opens with the following sentence, in which the task of explanation is divided into two parts: ‘These men [i.e. those described in this Treatise] will be composed, as we are, of a soul and a body. I must describe for you first the body on its own; and then the soul, again on its own; and finally I must show you how these two natures would have to be joined and united so as to constitute men resembling us’. The distinction of body and mind reflects Descartes’ strategy of attempting to explain all natural phenomena by analogy with complex machines, and of leaving for further work those features of human experience that seem to be inexplicable in this way. ‘We see clocks, artificial fountains, mills, and other similar machines which, even though they are only made by men, have the power to move of their own accord in various ways’. If the human body is created by God, then it follows that a divine artificer could construct a much more sophisticated machine than anything that results from human ingenuity. The apparently self-moving and self-controlling features of human bodies could therefore be explained by analogy with the machines in the royal gardens that had been designed to simulate the behaviour of animals and human beings.

“These had been described by Salomon de Caus, and they provided a model for constructing mechanical explanations of apparently non-mechanical phenomena. The machines in the royal gardens, which were able to ‘play certain instruments or pronounce certain words,’ relied on a complex but hidden hydraulic system of pipes. Descartes invites his readers to imagine that the human body is similar, with animal spirits substituted for water as the dynamic fluid. Despite the connotations of the name, animal spirits were nothing more than ‘a very lively and very pure flame’, that is, a type of subtle matter that was similar to the matter found in flames.

“This subtle matter was generated in the heart from blood and was then distributed throughout the body by circulation through the veins. For Descartes, all those features of animals that included movement and that required an explanation – such as the transmission of sensations to the brain and the responses that they trigger, and the controls exercised automatically by any animal over its own body – are explained by variations in the movement of animal spirits throughout the body.

‘I want to tell you first about the composition of the nerves and the muscles, and to show you how, from the sole fact that the spirits in the brain are ready to enter into certain nerves, they have the power to move particular bodily parts at the same instant. Then, after touching briefly on respiration and other similar, simple, and normal movements, I shall say how external objects act upon the sense organs. After that, I shall explain in detail all that happens in the cavities and pores of the brain, what route the animal spirits follow there, and which of our functions this machine can imitate by these means’.

“With this plan in place, Descartes offers schematic explanations of how the muscles move and thereby control bodily movements, how animals breathe, how they swallow food and drink and convert them to nutrients, and how ‘this machine is able to sneeze, yawn, cough, and to cause the motions needed to expel various excretions’.

“The same model can explain how ‘external objects that strike the sense organs can cause the machine to move its members’, and how the machine of the body can register these sensations in the brain. The mechanical explanations of hearing, feeling, smelling, and so on were sketched only in outline. In the case of sight, however, the work done in the years immediately prior to 1633 provided enough detail to hypothesize how an impression is formed on the back of an animal’s eye by the optic lens, and how this pattern is communicated to a part of the brain in which inputs from various sensory organs are synthesized. This synthesizing feature of the brain was called the ‘common sense’, in deference to its function, although its exact location was a matter of speculation.

“The hypothesis suggested by Descartes to account for sight was that the image formed on the retina causes a mechanically transmitted change in the centre of the brain. This pulling motion results in a release of animal spirits from the pineal gland in patterns that correspond, in some systematic way, to the images formed inside the eye. Descartes then suggested that the word ‘idea’ should be applied to the shape, form, or pattern assumed by this release of animal spirits. Descartes had argued, in the Rules, that there is an infinite supply of different geometrical shapes available by which one could model all sensations. He returns to this point in The World to suggest that the ‘figures’ or ‘shapes’ assumed by animal spirits, in response to various sensations, can vary systematically with the sensations themselves. These patterns, therefore, can provide an occasion for a human being ‘to sense movement, size, distance, colour, sounds, smells, and other such qualities; and even things that can make it sense pleasure, pain, hunger, thirst, joy, sadness, and other such passions’.

“It may come as a surprise that Descartes wanted to apply the term ‘idea’ to the flow patterns of animal spirits in the brain, but he is so explicit about this that it is impossible to avoid the implications of his claims. Objects that strike the senses cause many effects in the perceiver’s body. However, ‘it is not those imprinted on the organs of external sense, or on the inside surface of the brain, that should be taken as ideas, but only those traced in the spirits on the surface of the pineal gland, where the seat of the imagination and the common sense is’. Once ideas were understood as patterns in the flow of animal spirits to and from the brain, it was a short step to speculate about the imagination and memory as brain processes that resemble what happens in perception. Imagination is understood as an activity in the brain that results from those flows of animal spirits that arise spontaneously when an animal is not sensing any external stimuli; and memory is a disposition of the nerve ducts to conduct the spirits in patterns that resemble previous patterns.

“Descartes said at the outset of this treatise that he proposed to explain the body first, and then the soul. Accordingly, he refers at various stages to the addition of a ‘rational soul’ to the body and to the ways in which the ‘soul’ functions in causing sensations. However, the Treatise on Man concludes with an ambitious claim about the extent to which this rather speculative, hydraulic model has provided explanations of every animal function apart from those that are reserved for rational souls. Everything else about animal life is explicable in principle along these lines, and the outstanding features – for which a soul is required – remain to be specified and discussed further.

‘I desire that you consider that all the functions that I have attributed to this machine, such as the digestion of food, the beating of the heart and the arteries, the nourishment and growth of the bodily parts, respiration, waking and sleeping; the reception of light, sounds, odours, smells, heat, and other such qualities by the external sense organs; the impression of the ideas of them in the organ of common sense and the imagination; the retention or imprint of these ideas in the memory; the internal movements of the appetites and the passions; and finally the external movements of all the bodily parts that so aptly follow both the actions of objects presented to the senses, and the passions and impressions that are encountered in memory; and in this they imitate as perfectly as possible the movements of real men. I desire, I say, that you should consider that these functions follow in this machine simply from the disposition of the organs as wholly naturally as the movements of a clock or other automatons follow from the disposition of its counterweights and wheels. To explain these functions, then, it is not necessary to conceive of any vegetative or sensitive soul, or any other principle of movement or life, other than its blood and its spirits which are agitated by the heat of the fire that burns continuously in its heart, and which is of the same nature as those fires that occur in inanimate bodies’” (Clarke, pp. 121-4).

Garrison-Morton 574; Grolier Medicine 31; Guibert, pp. 196-97; Norman 627 (the variant issue); NLM/Krivatsy 3120; Osler 931; Tchemerzine II, p. 798 (describing two variants of the title-page, no priority mentioned); Waller 2376; Wellcome II, p. 453. Clarke, Descartes, 2006.

4to (208 x 158 mm), pp. [xxxvi], 123, [1], printer’s woodcut device on title-page, 10 engraved plates, one with overlays showing the interior regions of the heart, numerous engravings and woodcuts in text. Contemporary blind-ruled vellum (a bit soiled and spotted).

Item #5655

Price: $14,500.00

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