visit the 17th century mind The 17th century view of the Mind Here follows some notes on the shift from [The Brain Project] Galen's view of the mind and its body to the development of the mechanistic view. Part of The Brain Project by Stephen Jones. Galen's Humours Galen's view of human anatomy became the framework for all further consideration of the body and its brain for the next 1500 years. Investigative inquiry into the anatomy didn't begin until Nicholas Copernicus challenged the prevailing Church backed view of the world as the centre of the universe by showing that the earth and the planets moved around the sun; and William Harvey demonstrated that the blood was pumped in circulation around the body. But the concept of "pneuma" still held sway in any discussion of the brain. Rene Descartes wrote, in the mid 17th century, in reference to the ventricles: "The cavities of the brain are central reservoirs...animal spirits enter these cavities. They pass into the pores of its substance and from these pores into the nerves. The nerves may be compared to the tubes of a waterworks; breathing or other actions depend on the flow of animal spirits into the nerves. The rational soul (the pineal) takes place of the engineer, living in that part of the reservoir that connects all of the various tubes. These spirits are like the wind. When they flow into a muscle they cause it to become stiff and harden, just as air in a balloon makes it hard." [Bergland, p61] [Image] Robert Burton in The Anatomy of Melancholy (first published in Title page from Robert London in 1652) represents the Burton's The Anatomy of "humours" view based on Galen. Melancholy, 1651. [from the His book is possibly the first 1849 edition in Stephen major treatise on a psychological Jones' library] problem, namely depression, ever published. Burton summarises the state of anatomy with discussion of the humours. The four humors were: blood [sanguine] a hot, sweet, temperate humour whose office is to nourish the whole body,to give it strength and colour. pituita [phlegm] a cold and moist humour, his office is to nourish and moisten the members of the body. choler [yellow bile] hot, dry, bitter, helps the natural heat and senses, and serves to the expelling of excrements. melancholy [black bile] cold, dry, thick, black, and sour. He also adopted the Aristotelian views on the nature of "life" referring to spirits: "Of these spirits there be three kinds, according to the three principle parts, brain, heart, liver; natural, vital, animal. The natural are begotten in the liver and thence dispersed through the veins, to perform those natural actions. The vital spirits are made in the heart of the natural, which by the arteries are transported to all the other parts: if the spirits cease, then life ceaseth, as in a syncope or swooning. The animal spirits formed of the vital, brought up to the brain, and diffused by the nerves, to the subordinate members, give sense and motion to them all." [Burton, p94] and the soul (or the anima) which was divided "into three principle faculties - vegetal, sensitive, and rational, which make three distinctive kinds of living creatures - vegetal plants, sensible beasts, and rational men. How these three principle faculties are distinguished and connected...is beyond human capacity,... The inferior may be alone, but the superior cannot subsist without the other; so sensible includes vegetal, rational both; which are contained in it (saith Aristotle) as a tringle in a quadrangle." [Burton, p98] He then goes on to describe the brain as a device for distilling the animal spirits: "...the brain...is a soft, marrowish, and white substance, engendered of the purest part of seeds and spirits, included by many skins, and seated within the skull or brain pan; and it is the most noble organ under heaven, the dwelling-house and seat of the soul, the habitation of wisdom, memory, judgement, reason and in which man is most like unto God; and therefore nature hath covered it with a skull of hard bone, and two skins or membranes, whereof the one is called dura mater, or meninx, the other pia mater. The dura mater is next to the skull, above the other, which includes and protects the brain. When this is taken away, the pia mater is to be seen, a thin membrane, the next and immediate cover of the brain, and not covering only, but entering into it. The brain itself is divided into two parts, the fore and hinder part; the fore part is much bigger than the other, which is called the little brain in respect of it. This fore part hath many concavities distinguished by certain ventricles, which are the receptacles of the spirits, brought hither by the arteries of the heart, and are there refined to a more heavenly nature, to perform the actions of the soul. Of these ventricles there are three - right, left, and middle. The right and left answer to their site and beget animal spirits; if they be in any way hurt, sense and motion ceaseth. These ventricles, moreover, are held to be the seat of the common sense. The middle ventricle is a common concourse and cavity of them both, and hath two passages - the one to receive pituita, and the other extends itself to the fourth creek; in this they place imagination and cogitation, and so the three ventricles of the fore part of the brain are used. The fourth creek behind the head is common to the cerebral or little brain, and marrow of the back bone, the last and most solid of all the rest, which receives the animal spirits from the other ventricles, and conveys them to the marrow in the back, and is the place where they say the memory is seated." [Burton, p97] And so in referring to the cause of disease and paricularly mental dis-ease he says: "...as the body works upon the mind by his bad humours, troubling the spirits, sending gross fumes into the brain, and so per [Image] consequens the ....................forgotten faculties of it, with quite fear, sorrow, &c., All former scenes of which are ordinary dear delight, Connubial symptoms of this love .... parental joy disease [melancholy]: ...... so on the other side, No sympathies like these the mind most his soul employ; effectualy works upon But all is dark within the body, producing by ......... his passions and [Penrose. from the perturbations frontispiece to Burton's miraculous The Anatomy of alterations, as Melencholy, 1849 melancholy, despair, edition] cruel diseases, and sometimes death itself." [Burton, p164] To revue Burton: The rational soul was seated in the brain, and received sensations and controlled movement, via the action of the fluid 'animal spirit'. The emergence of the mechanistic view. It took a very long time and much valiant work (vide: Nicholas Copernicus and Giordano Bruno) to begin the liberation of science from the overarching control of the mystico/religious framework and the political needs of the Roman Church. This change started to really happen at the end of the 16th century with the appearance of a new attitude to the observation of what actually happens, followed up by a desire to experiment on and test what is being observed. But at this early stage the mystical framework still greatly influenced theory. In A Short History of Science, Charles Singer notes Kepler's mystical adherence to the Pythagorean/Platonic solids and to the idea "that the arrangement of the world and its parts must correspond with some abstract conception of the beautiful and the harmonious" [Singer, 1941, p200]. Referring to Kepler's first approximation of his theory of the orbits of the planets, Singer says: "That Kepler sought so persistently for a simple mathematical scheme of the material world, and that, having found one, he regarded it as fitting his scheme of the moral world, suggests certain reflections on the workings of the mind itself. Whatever reality may be, we seem to be so made that we aspire towards an interpretation of the universe that shall hold together in a complete and reasonable scheme. The fact that we thus aspire does not in the least prove that such a scheme corresponds to reality. Nevertheless, all great religions attempt to provide such an interpretation. All become skillfully 'rationalised'.[Singer, 1941, p203] It looks awfully like Singer adopts a vitalistic view of science here: that the motivation of science is to find a unified view of the "world" and that this in some way is a "natural" function of the mind. Yet this has considerable political consequence... "It is because science disturbs part of this already carefully rationalised field that religion resents its intrusion. The mind recoils from a dualistic universe, and rationalised religion usually seeks to minimise even such remnants of dualism as the conception of a spirit of evil. It is easy for us now to regard the opponents of Galileo and Kepler as purblind fools. Base motive certainly prompted some of the opposition; but in essence the opposition expresses the reluctance of the human mind to adopt any teaching which disturbs it unitary conceptions. A reasoned view of the universe, physical and moral, had grown up during the Middle Ages. It would have been indeed a marvel if this had been relinquished without a struggle, for faith is not necessarily accompanied by either wisdom or learning or foresight." [Singer, 1941, p203] The 17th century was a most remarkable period in its extraordinary fecundity of quite revolutionary ideas. That the earth travelled around the sun was only now being established. Copernicus had really only found that the Ptolemaic system of the Medieval period had too many anomalies (the epicycles) to allow it to stand against observation any longer. It took Kepler and Tycho Brahe to get the really useful data that allowed Galileo to finally publish (much to his trouble) his great synthesis Dialogues on the Two Great Systems of the World Galileo conceived the world as reducible to measurement and mechanical principle. He was first to exploit the telescope and also instituted the use of [Image] telescopes and microscopes of Title page of the Dialogues high craftmanship as tools of on The Two Great Systems of investigation. That the heavens the World by Galileo Galilei were vast and complex with a (3rd edition, 1641) [from multiplicity of worlds was now Stephen Jones' library] mirrored in the startling multiplicity of matter and life in the microscopic world. Francis Bacon in The Proficiencie and Advancement of Learning and Rene Descartes in his Discours on Methode laid down the principles of experimental science which we still follow. Firstly one should gather all the facts that are relevant to the matter being investigated. This selection of relevance is based on the work of one's predecessors with which one is familiar through study. Having gathered all the facts one forms them into an Hypothesis which links all the facts together. Then one tests the hypothesis by experiment, modifying the hypothesis as required by the results of its testing. It is this which finally allows the development of a Theory. With Galileo's development of the science of mechanics came the attempts by the biologists to explain the animal body as a machine. It becomes apparent to the experimental philosophers of the 17thC. that one might hunt out principles of a mechanical nature which applied alike to the motions of the heavens as they did to the earth and to living things. The world view of science becomes increasingly mechanistic. For example, in 1615, William Harvey discovered the process of the circulation of the blood and thus that the heart is a pump. The mechanical model of the heart as a pump stands as an early version of the process of using a working mechanical model to form a clearer picture of some part of the animal body. The classical microscopists, Malpighi and Leeuwenhoek, "discovered the corpuscles of the blood, the secretory functons of 'glands', and the fibrillary character of muscles, thus helping to complete details of the animal machine." (Singer, 1941, p243). The Rise of Anatomy Uptil Descartes the rational soul was intimately housed in the brain. The humours which supported the activities of the various souls running the person could be seen and their pathways mapped (to a limited extent, given the difficulties in carrying out anatomical investigation, in obtaining bodies, imposed by the Roman church). The vegetal soul is in the liver, the animal soul is in the heart and the rational soul in the brain. The role of Authority in teaching could not allow the questioning of handed down wisdom, especially as that wisdom was held by the Roman Church. During the darkness of the middle ages, the Church was the sole repository in Europe of the books and knowledge emmanating from the Greeks and the Romans. The Arab world had kept up a continuing spirit of inquiry through the middle ages but this material did not become available in Europe until it filtered out through the Moorish colonisation of Spain. Any re-appearance of information was controlled by the Church, they had control of the books and the institutions of learning, which, immediately before the Rennaisance where confined to the monastries. They also carried the ideological power, to maintain the position of authority of the Church, with the Pope as God's representative on earth, essentially bestowing upon him the supreme right of decision making. As with the clerical hierarchy so was there a hierarchy of social relations and a hierachy within the person and their body. The rational soul was available only to humans. The animal and vegetal souls, available to animals as well, were enough to deal with the bodily needs, both long term and everyday. The head was given a superior value through its position on top of the body and so it must be the seat of the rational soul. Further in what anatomical work was done, the main arteries carried the 'sanguine' to the head, and it was there that the vital spirit, the 'pneuma' was distilled out of the blood and distributed through the body by the nerves. So as the Pope was the head of the Church, and the man was the head of the household, the skull housed the brain which must be the head of the body. Descartes reduced the humoural description of the body/brain with its variety of souls to a mechanical/hydraulic model. He used the most celebrated technological achievements of his time as his analogy. The great waterworks of fountains and water driven clocks and automatons, the showpieces of men of power, provided Descartes with models for describing how the brain operated the muscles and the general description of nerve process. But where now is the soul? Descartes demonstrated philosophically that we needed the capacity to keep some sort of 'reason-able' continuity, and the Church ideology demanded some sort of spiritual man which would be able to have continuity after [Image] bodily death to keep its Title page from Descartes' carrot-and-stick control over the Opera Omnia (Collected lives of its subjects and the Works) 1692 [from Stephen source of its cash-flow. Thus a Jones' library] purely mechanical model of the human would not do. So Descartes divided the soul or the mind, the thinking thing, from the body and established Dualism as a way of thinking. By a process of radically doubting everything of which he could not be absolutely certain, all sensation, movement, bodies, physical things were rendered unreliable. Finally only 'I' could be said to exist, I the thinking thing. All else is perceived only by a process of understanding, mediated by the mind. So there is that about which Descartes is certain, i.e. the thinking thing, and there is everything else. He has separated the mind from all the world of sensations and physical things. It could be argued that all Descartes really did was to separate the phenomenal from the physical. This had two consequences: for the physical, biological scientist it allowed ever more detailed and effective analysis of problem of elucidating what it is that allow living systems to work, but for the philospher it so utterly misdirected the agenda for understanding the phenomenal, the mind, that we still have not completely escaped its effect. Dualism still rides with us and the religious view still has enormous sway over the physical/biological sciences. Descartes ruptured "the traditional stair of life ranging upward step by step to man. Science since Descartes has repaired the stair and finds it more significant than before. It marks the way that man has climbed. And it is a stair of mind as well as body, and it is without break, man's mind nothing more than the topmost rung continuous with related degrees below." [Sherrington, 1940, p186] In a sense it is the ongoing closure of the gap, opened up by Descartes, between body and mind which has become the characteristic of the development of neuroscience ever since. The increasing localisation of function and the increasing visual and conceptual magnification of the means of exploring the brain, show us more and more that the fine structure of the processes of the brain, the chemistry, interneuronal linking and organisation, can account more and more for the operations carried on. On the role of modelling When we make a tool we project ourselves onto the world. We create something which fits a mental model of the tool to achieve some goal, from turning over a large piece of rock with a stick used as a lever, to creating a mechanism in metaphor with which we can manipulate and represent our idea (eg. our idea of ourselves). We seem to want to be able to explain the world in terms simpler than the operations of the world, i.e. reductionism. The models we use will in general be the latest or the most acceptable depending on how conservative we are. We need laws, spiritual or temporal to fix our relationship with the world and nature and God, if we consider the latter to be necessary. With the rise of a mechanistic description of the workings of inanimate nature, new models of how animate nature might work can be generated and thus the models of the animal as a machine. "A machine being a man-made contrivance, to call a living organ a machine implies that it is mechanism humanly intelligible. The whole man being organs the implication is that the whole man is mechanism humanly intelligible." [Sherrington, 1940, p.186]. Perhaps here lies the key to the mechanistic modelling, it is the urge to understand and the opportunity offered by modelling which drives the whole process. The spiritual/religious explanation denies the option of actually understanding the processes of nature while the mechanistic starts with the view that nature can be understood. ---------------------------------------------- References: Bergland, R. The Fabric of the Mind. 1985 Burton, R. The Anatomy of Melancholy. 1811 Sherrington, Sir C. Man on his Nature. 1940 Singer, C. A Short History of Science. 1941