Rene Descartes
Physiological-Minded Philosopher and Mathematician

Henry G. Barbour
Professor of Physiology and Pharmacology
University of Louisville
January 10, 1927


            Rene DesCartes was born in La Haye in Touraine, March 31, 1596, the son of Joachim DesCartes who brought the family into the lower nobility of France by gaining certain legislative offices. His property was known as du Perron, however when eligible, declined to use the title Monsieur du Perron. Rene’s mother died at his birth, leaving an older son who followed a political career and a daughter who married.  Rene had little in common with and was little appreciated by his family whom he rarely visited. He was an extremely delicate child and owed his life to the care of a devoted nurse who was with him many of his first years. DesCartes’ formal education was obtained chiefly from 1604-12 at the Jesuit School at LeFleche, founded by Henry IV.  Here a number of privileges were granted DesCartes because of his feeble constitution.

            Before leaving school at the age of 16, he had begun to mistrust tradition as guide to knowledge and conduct.  He acquired at LaFleche a habit of reflection in bed on awakening, under which circumstances much of his life’s work was done. Henry IV died while Rene was at this school and he was one of twenty-four youths selected to carry the King’s heart to its final resting place at LaFleche amidst very elaborate ceremonies. After leaving school, he entered first upon the life of a young Parisian aristocrat but seems to have steered clear of the less desirable features, although said to have acquired a temporary passion for gambling.  He perfected himself in horsemanship and fencing, and also developed a friendship with Father Mersenne whom he had first known at LaFleche, and who was devoted to him throughout his life.

            DesCartes took up a military career for a number of years, and under Prince Maurice of Orange received what appears to have been his only pay during life; this he kept as a souvenir.  In 1619 DesCartes entered the Bavarian service against the King of Bohemia and was present at the battle of Prague in 1620. Of those who then precipitately fled from Prague was the little Princess Elizabeth then aged four, who later became a philosophical correspondent of DesCartes.

            While encamped at Heuberg on the Danube on the Eve of St. Martin 1619, DesCartes describes a psychological experience in which there entered his mind “the foundation of a marvelous discovery.” This was associated with three distinct dreams which have afforded material for some subsequent theological discussion. The interest lies in the fact that DesCartes definitely dates his fundamental philosophical convictions from that night. Having much military leisure he had been working at high tension developing the conception of the application of algebra to geometry.  His “marvelous invention” seems to have been the conception that by comparing the mysteries of nature with the laws of mathematics, a common key to the secrets of both would be found. This lofty conception of the unity of all things in the universe, material and immaterial, under one system of laws is indeed the foundation of that philosophy which most nearly satisfies the modern mind; DesCartes’ life was largely devoted to its development. While most of his superstructure has since been swept away, a continually increasing importance has become attached to the fundamental notion of “mechanism.”

            Following his military experience, DesCartes spent some time in the northern central portion of Europe, at which time and experience on the North Sea nearly deprived the world of his contributions. Traveling with one or two companions they trusted their lives and goods to a boatman who conceived the idea that it would be profitable to bring DesCartes’ property to land without its rightful owner.  The plot was discussed with the other sailors in a language mistakenly supposed to be unintelligible to the distinguished passenger. DesCartes, however, drew his sword and assumed control over the brigands until landing.

            In 1622, property was inherited yielding DesCartes something better than $2500.00 annually; he now enjoyed a very comfortable income for a bachelor of that day. A photograph of one of the houses which he later owned in Enegeest, Holland, has been reproduced by Mies Holdane and affords some evidence of DesCartes’ property.

            For a while DesCartes settled down in Paris to devote himself to science and philosophy. On the more practical side of his interests was in the grinding of lenses.  In spite of expert assistance, however, his productivity in this line could not keep pace with his mathematical speculations on optical subjects; he could invent more intricate lenses than he could produce. DesCartes at this time became increasingly annoyed by social distractions and one day suddenly disappeared from his circle of friends, to devote himself more exclusively to contemplation and scientific work. Before long, however, one of his friends encountered DesCartes’ valet and through him traced the master to his lair.  There he reconnoitered through the keyhole.  It was 11 o’clock in the morning ad the philosopher was seen meditating in his bed, occasionally half raising himself for the purpose of making notes.  When finally arose, the intruder made himself known and DesCartes found himself again drawn into his former social relations.  For this and other reasons, the philosopher withdrew to Holland where he resided from 1628 to 1649, the last year of his life.

            One of the incidents of most significance in establishing DesCartes’ fame and bringing his work to general notice was his invitation by one of the cardinals, to an assembly of learned men for the purposed of listening to a new system of philosophy propounded by a Dr. Chandoux. This man, after refutation of the old methods of the schools elaborated a philosophical system of which he falsely claimed to be the originator.  The exposition was well applauded but Cardinal de Burulle who was present, by repeated urging persuaded the reticent DesCartes to express his feeling in the matter. DesCartes, after complimenting the speaker on his form of presentation and his talents, particularly applauded his thesis, --- the Liberation of Philosophy from Scholasticism.  DesCartes said, however, that he believed that the lecturer had confused probability with truth, a circumstance which inevitably led to downright error.  His development of the conception is well described by Mies Haldane in the following words:

            “Then he suggested that someone present should propound any apparently incontestable fact, which was done. By twelve arguments, the young man then showed it to be false.  The operation was repeated, starting with an obvious falsehood, and by similar probably arguments its truth was clearly demonstrated.  The company was astonished both at DesCartes’ genius and the ease with whey they found their minds made the dupes of seeming truth; at once they asked if he could show them how to avoid such sophisms, and he replied that he knew no better method than that which he himself made use of, founded upon a mathematical basis; and he did not believe there was any truth which could not be clearly demonstrated by its means, and following proper principles.  Of course this was the famous Method, by the which the proposition was first of all found to be a possible one, after which its solution was discovered by a mathematically certain sequence of reasoning.  The opportunity for demonstration this newly found principle - - - whose newness sounds strangely to us now - - - was a great one, and DesCartes was fully conscious of its importance, as is shown by his allusions long  years afterwards.  The occasion was doubtless a remarkable one, since it gave the philosopher – still comparatively young – the opportunity of publicly asserting himself, and taking the place in the world of learning to which his talents entitled him.”

            The Cardinal de Berulle became greatly impressed and on a later occasion DesCartes visited him and explained how the method could be applied to medicine and mechanics.  The Cardinal in turn showed DesCartes that he was responsible to God for giving mankind what he had been fortunate enough to have delivered to him.  While encouragement from the eminent ecclesiastic was no doubt stimulating there is little question that the work of the philosopher at this stage was bound to ripen without it.

            Holland, DesCartes found very well adapted to the kind of life he desired to lead.  In spite of the more rigorous climate, he enlarged in writing to his friends upon the better facilities for maintaining bodily comfort in a cold locality than in one (e.g. Italy) where the heat is too severe.  He enjoyed going about Amsterdam with a feeling of solitude although in the midst of a lively civilization.  In 1636, he abandoned his determination to avoid publication and sent a manuscript to Father Mersenne, his counselor on many matters, carrying this remarkable title:  “The Project of a Universal Science which can raise our nature to its highest degree of perfection. The Dioptric, Meteors, and Geometry in which the most curious matters which the author could select to show evidence for his proposed universal science are explained in such a manner that even those who have not studied, can understand.”  As finally published the work bore the more modern title: “Discourse on the method of properly guiding the reason in the research of Truth in the Sciences.   Also the Dioptric, the Meteors, and the Geometry, which are the Essays of this Method.”  DesCartes’ famous Method first published in this fashion was built upon the following four principles of elementary logical thought:

            “The first was never to accept anything for true which I did not clearly know to be such; that is to say, carefully to avoid precipitancy and prejudice, and to comprise nothing more in my judgment than what was presented to my mind so clearly and vividly as to exclude all ground of doubt.”

            “The second, to divide each of the difficulties under examination into as many parts as possible, and as might be necessary for its adequate solution.”

            “The third, to conduct my thoughts in such order that, by commencing with objects the simplest and easiest to know, I might ascend by little and little, and as it were step by step, to the knowledge of the more complex; assigning in thought a certain order even to those objects which in their own nature do not stand in a relation of antecedence and sequence.”

            “And the last, in every case to make enumerations so complete, and reviews so general, that is might be assured that nothing was omitted.”

            “The Dioptric,” “Meteors,” and “Geometry” were all notable presentations of these subjects.  In the first of these was discussed the use of various types of lenses with elaborate diagrams illustrating amongst other things the use of telescopes.  DesCartes expounded the law of refraction without however giving credit to its discoverer, Snell.  He contributed to the science of dioptrics some fundamentals of the undulatory theory of light.

            In “Meteors” are treated the various phases of meteorology, with chapters on winds, clouds, snow, etc.  Of especial importance was the description of the rainbow with a figure sometimes employed in present day physics textbooks.  For here was expounded, for the first time, the secret of the spectral display, -- double refraction in each sphere of water.  The diagram illustrating the atmosphere illustrates DesCartes’ view of the entire universe as a “continuum” or “plenum” as opposed to the atomic theory which allows of empty spaces.  The notion is thereby avoided that a body can influence another through an intervening vacuum.  This discussion has been carried on since the time of the ancients, the doctrine of continuity having been held by Heraclitus and Aristotle.  DesCartes’ “continuum” was originally solid matter which became divided up into parts that began to revolve and grind each other’s corners off until there resulted the heavenly spheres interspersed with cosmic dust.

            Since DesCartes’ time the doctrine of the continuity of matter has usually had the upper hand, for until very recently physicists have depended upon the hypothesis of an elastic ether to explain the transmission of light. The extreme point of view was attained by Sir Oliver Lodge who stated about fifteen years ago that the “ether is turning out to be the most substantial thing in the universe,” a claim made under the influence of a belief in the “ectoplasm” of spiritualism.  With the advent, however, of the  quantum theory it is now maintained that the ether is an unnecessary conception.  Apparently our ideas of time and distance all have to be revised, and according to Professor Gilbert Lewis of California, the eye touches a star just as truly as the finger an adjacent object.  Again, according to others, we may consider each atom as at all times invading the entire universe, a conception based upon certain discoveries in radiology.

            DesCartes’ “Geometry” contains three chapters: (1) Problems requiring only straight lines and circles, (2) The nature of curved lines, (3) The construction of solid or supersolid problems.  He takes issue with the ancients for calling the subject matter of the second and third chapters “mechanical” and therefore inexact, because requiring the use of instruments.  Why the distinction? The ruler and compass required for straight lines and circles are also instruments; say rather all geometry is exact.  In the first pages one is taught the method of multiplication, extraction of square roots, etc., by the use of geometrical figures.  The geometry closes with the astonishing remark, “I hope that posterity will judge me kindly not only as to the things which I have explained but also as to the things which I have intentionally omitted so as to leave to others the pleasure of discovery.”

            DesCartes early proficiency in mathematics is illustrated by the incidents of his chance introduction to Isaac Beechman, Principal of the College at Dort, a philosopher and mathematician of eminence.  While soldiering at Breda when scarcely come of age he stopped in the street to read a placard upon which someone had announced a mathematical problem with a challenge to find the solution.  Being unable to read Flemish, DesCartes asked a bystander kindly to translate it into either French or Latin for him.  The stranger who happened to be Beeckman did so after sarcastically imposing the condition that DesCartes should solve the problem. Next day the younger mathematician astounded the elder with the solution; they became friends and life-long correspondents.  Unfortunately, Beeckman seems to have in later years paraded as his own a treatise on Music which DesCartes had at one time loaned him the MSS.

            The Contributions made by DesCartes to mathematics are summarized by Mahaffy partly as follows:

            “(1)  He was the first to place on a clear basis the doctrine of powers, freeing it from its connection with geometry, which prevented its proper expansion.  At the same time, by the introduction of the index notation, he conferred on the science a new and most potent organ of expression.”

            “(2)  The treatment of negative quantities (e.g., negative roots) was also much advanced by him.”

            “(3)  But the leading discovery of DesCartes in mathematics, and that on which his fame as a mathematician mainly rests, is unquestionably the application of algebra to geometry; or rather, to use Playfair’s words, ‘The expression by means of algebra of continuously varying quantity.’  In fact, DesCartes, in virtue of this invention, must be considered not only as the founder of the science (since his time so largely extended) or analytic geometry, or the algebraic treatment of curves – he was also the pioneer in the path which led up to the greatest discovery in modern mathematics, that of the Differential Calculus, by Newton and Leibnitz.

            Whenever we express our results graphically whether they deal with a patient’s temperature or the relations obtaining between wind velocity and one’s golf score we habitually refer to them as “Cartesian” coordinates.

            The “Principles of Philosophy” appeared in 1644.  Here, as is well known, DesCartes endeavored to sweep aside all preconceived ideas and convictions and to discover as much as possible of the truth  de nova.  This brought him down to the basic idea that the most definite reality in the  universe is thought:   “Cognito, ergo sum.”

            “The first principle of his philosophy is, that our consciousness is truthful in its proper sphere, also that our thought is truthful and trustworthy under these two conditions --- when the thought is ‘clear and vivid’, and when it is held to a theme utterly distinct from every other theme; since it is impossible for us to believe that either man who thinks, or the universe concerning which he thinks, is organized on the basis of a lie. There are ‘necessary truths’ and they are discoverable.

            A second principle is, the inevitable ascent of our thought from the fragmentary to the perfect, from the finite ‘innate idea’, a part of man’s potential consciousness.  This principle is the Cartesian form of the a priori argument for the Divine existence, which like other a priori forms is viewed by critics not as a proof in pure logic, but as a commanding and luminous appeal to man’s entire moral and intellectual nature.

            A third principle is, that the material universe is necessarily reduced in our thought ultimately to two forms, extension and local movement --- extension signifying matter, local movement signifying force.  There is no such thing as empty space; there are not ultimate indivisible atoms; the universe is infinitely full of matter.

            A fourth principle is, that the soul and matter are substances so fundamentally and absolutely distinct that they cannot act in in reciprocal relations.”

            On the question of soul and body, DesCartes was severely criticized for developing a dualism instead of the monism with which he started out.  The soul, he conceived of as without extension, an attribute only of matter.  The soul, however, resides in the body and within the pineal gland which apparently it does not fill, but where it seems to resemble a mathematical point.   DesCartes’ identification of the soul with the ego led one of his chief opponents, Gassendi, ironically to address the philosopher, “Oh Soul”, to which DesCartes naturally retorted, “Oh Body”.  The thinking soul he divides into:  the will which is infinite and unfettered being the most Godlike attribute of man, and the intellect which is limited by recognized conditions.  The latter seems to include the sensations as well as the perceptions.  DesCartes was a sincere believer in God, a fact which must be kept in mind when considering his very obvious tendency at times to flavor his philosophy somewhat to the taste of his theological friends.  He speaks of the contemplation of God as the greatest happiness which mortals can attain.   Apparently he did not reconcile the spirit with matter through God as completely as was done by his follower, Spinoza.  This Jewish savant and Malebranche, Catholic and ascetic were the two followers who upheld and developed the above outlined principles of Cartesianism.

            This first movement of modern philosophy asserted and exhibited the unity of the intelligible world with itself and with the mind of man.  Leibnitz says that DesCartes’ teachings are the anti-chamber to the truth and gives unreserved praise to his pioneering stimulus.  Schopenhauer, calling DesCartes the “father of the new philosophy”, says that he introduced the art of standing on one’s own feet.  He taught men to use their own heads on all questions, even those held to have been finally settled by the Bible on the one hand or Aristotle on the other.  He first tried to separate objective from subjective and so clearly expressed this that he is “the Atlas on whose shoulders the entire modern philosophy rests”.  A definitely “scientific attitude” had been very ably exhibited and to appreciate the influence which this exerted, we must remind ourselves of the firm hold which scholasticism held in DesCartes’ time upon nearly every thinking man.

            For the Innominate Society the greatest interest attaches to the value of DesCartes’ contributions to medicine.  Our debt to him at once appears great when we realized that he contributed what is spoken of as the first complete textbook of physiology.  This “Treatise on Man” was published posthumously by the editor, Clerselier in 1662, the most correct edition appearing in 1667.  Through the kindness of Professor Leake of Wisconsin, I am able to show you a copy of this edition.  While most of the physiological details here set forth would hardly bear the scrutiny of present-day, it is remarkable how clearly many lines of interpretation were laid down.  One of the most interesting of these concerns reciprocal innervation.  DesCartes’ diagrams illustrate the application of this principle in the case of two opposing muscles of the eye.  The animal spirits are delivered by the pineal body to the motor nerves in question, which serve as pipelines for their conveyancy to the muscles.  At the periphery a double cross connection provides that each muscle is served by the motor nerve of its antagonist as well as by its own motor nerves.  The cross nerves are so equipped with valves that the fluid pressure of the animal spirits on the one side automatically prevents the ingress of fluid to the other side.  Physiologists now understand that the nerve impulse passes as a disturbing wave rather than as a forward movement of fluid or other material, and furthermore refer reciprocal inhibition to the central nervous system; in other respects today’s conception of the phenomenon cannot be said to be far in advance of the scheme of DesCartes.

            In spite of DesCartes’ knowledge of Harvey’s contemporaneous discovery of the circulation to which he made courteous reference, he continued to subscribe to the Galenic doctrine of the innate heat of the heart. This illustrated in the following citation translated from the Latin by Sir Michael Foster:  ---After speaking of the “formation of blood in the liver out of the chyle of the food”, he continues thus: ---

            “Now this blood has one obvious passage only by which it can get out, namely that one which carries it into the right cavity of the heart; and you must know that the tissue of the heart contains in its pores one of those fires without light of which I spoke above, which makes it so hot, so ardent that no sooner does the blood enter into one or other of the two chambers or cavities which are in the heart than it immediately expands and dilates, just as you would find the blood or the milk of an animal would do if you were to pour it drop by drop into a vessel which was very hot.  And the fire which exists in the heart of the machine which I am describing serves no other purpose than that of expanding, heating and as it were subtilizing the blood which falls continually drop by drop, through the channel of the vena cava into the cavity of its right side, whence it is exhaled into the lung, and from the vein of the lung, which the anatomists call the vein-like artery, into the cavity of the other side, whence it is distributed over the whole body.”

            Curiosity as to the fascinating speculations of DesCartes on the relation of the circulation to the lungs and the brain will be well rewarded by reference to further passages cited in Foster’s “History of Physiology”.  We must pass on to those which set forth that most illumination conception of our physiologic philosopher, the Reflex:

            “Now as these spirits enter thus into the ventricles of the brain, so they pass thence into the pores of its substance and from these pores into the nerves.  And according as they enter or even only as they tend to enter more or less into this or that nerve they have the power of changing the form of the muscle into which the nerve is inserted and by this means of making the limbs move.  You may have seen in the grottoes and fountains which are in our royal gardens that the simple force with which the water moves in issuing from its source is sufficient to put into motion various machines and even to set various instruments playing or to make them pronounce words according to the varied disposition of the tubes which convey the water.

            And indeed one may very well compare the nerves of the machine which I am describing with the tubes of the machines of those fountains, the muscles and tendons of the machine with the other various engines and springs which serve to move these machines, and the animal spirits, the source of which is the heart and of which the ventricles of the brain are the reservoirs, with the water which puts them in motion.  Moreover breathing and other like acts which are natural and usual to the machine and which depend on the flow of the spirits are like the movements of a clock or of a mill which the ordinary flow of water can keep going continually.  External objects, which by their mere presence act upon the organs of sense of the machine and which by this means determine it to move in several different ways according as the parts of the machine’s brain are disposed, may be compared to strangers, who entering into one of the grottoes containing many fountains, themselves cause, without knowing it, the movements which they witness. For in entering they necessarily tread on certain tiles or plates, which are so disposed that if they approach a bathing Diana, they cause her to hide in the rose-bushes, and if they try to follow her, they cause a Neptune to come forward to meet them threatening them with is trident.  Or if they pass in another direction they occasion the springing forward of a marine monster who spouts water into their faces, or things of a like kind according to the caprices of the engineers who constructed them.

            Lastly, when the rational soul resides in this machine, it has its principal seat in the brain and may be compared to the fountaineer who has to take his place in the reservoir whence all the various tubes of these machines proceed whenever he wishes to set them going, to stop them or in any way to change them.”

            In his conception of the reflex control of the nervous system over motor action, DesCartes gets on to solid ground.  The notion of the entire body as an automaton, so extremely illuminating in that day, is but just coming into its own; the great intellect of Pavlov, has here exerted no small influence.

            As is well known, DesCartes’ speculations upon the soul led him to a most unfortunate distinction between men and the lower animals, which deprived the latter of all conscious sensation; their cries of suffering from a machine when something breaks off and gets into the wheels.  His more immediate followers are said to have brought physiological investigation into some disrepute by a stupid lack of consideration for the feelings of animals.

            Mies Haldane cites a strange tale circulated by DesCartes’ enemies to the effect that he had made with much ingenuity an automaton in the form of a girl, in order to prove that living beings are mere machines.  DesCartes was said to have taken this automaton on a vessel, packed in a box.  The captain had the curiosity to open the box, and as the figure appeared to have life he took it for the devil and threw it overboard.

            DesCartes himself made dissections and experiments upon living animals but be in emphasized that this fact did not make him a true physiologist, for he neglected the inductive method.  He began his work with preconceived hypotheses and the subsequent experimental demonstration rather than being utilized to teach new facts was always forced to serve as proof of the preconceptions.  On the other hand DesCartes admits that his treatise on physiology is not a perfect exposition of this science, but rather intended to show how a material machine might be constructed capable of functioning in all respects like the human body.

             For the above reasons it seems appropriate to describe DesCartes as “physiologically-minded philosopher”.  He believed that sadness rather than joy prompted appetite and healthy sleep.  This was based on personal experiences.  He practiced also a profound belief in vegetarianism and in a very limited use of alcoholic beverages.

            DesCartes had a great interest in the possible applications of scientific medicine.  At one period he set out to contrive means of prolonging human life, in fact went so far as to advise a sick friend to hold on until he had completed his method for securing immortality.  He was also interested in getting at the chemical processes of physiology and was far in advance of his day in expressing hopes of using them as a basis for treatment.  DesCartes physiological “Treatise on the Formation of the Fetus” is also a remarkable contribution.  Much is described in astonishing minuteness and at the time it seemed as though at last a real physical-chemical explanation of life had been found.  A publication on the theory of medicine appears never to have emerged from the contemplation stage; likewise a discussion of plants which undoubtedly would have contained much of value.

            With all DesCartes’ breadth of interest it is somewhat surprising to learn of his contempt of things aesthetic; imagine a residence of 21 years in Holland contemporaneous with the production of Rembrandt’s masterpieces and not a word of mention of them in DesCartes’ most varied writings.  At a later period he refers with some contempt to the fact that the Queen of Sweden was engaged in the systematic study of certain Greek authors.  DesCartes’ intolerance also extended even to books in general; of these he possessed almost none.

            He further showed contempt for the remarkable advances in made by his contemporary, Galileo.  DesCartes made a point, while traveling in Italy, of avoiding the latter’s place of residence.  He says that he spent two hours turning the leaves of Galileo’s famous book but that there was nothing in it.  How much of this attitude was affected to keep in the good graces of the Catholic Church one does not know.  Certainly the way in which Galileo was treated made a profound impression on DesCartes, who upon learning of Galileo’s punishment, at once indefinitely postponed many ideas of publication.   Hence the “Treatise on Men” did not appear until twelve years after DesCartes’ death.  Of a contemplated book entitled “The World” only an abstract remains.

            An example of adaptation of science to meet the demands of dogma is seen in DesCartes’ theory of stellar vortices.  The ecclesiastics would not allow the world, which is the center of the universe, to move.  Hence to carry it in its annual excursion around the sun, DesCartes proposed the astounding subterfuge of a mass or vortex of gaseous material in which the world rests as in a cradle.  Such vortices carry the earth and other planets through their orbits and the earth remains as the ecclesiastics would have it, quite stationary, like a passenger sitting in his chair on an ocean liner.  DesCartes may have half believed this, himself as it gave him some padding for his “continuum”’; at all events, he was not in the least disposed to become a martyr.

            Controversies occupied much of the later part of DesCartes’ life.  Some of the most intense centered about his famous work “Meditations Concerning the First Philosophy in which are demonstrated the Existence of God and the Immortality of the Soul”.  The “Meditations” resulted in the publication by opponents of seven series of objections.  These together with DesCartes’ replies form a tremendous mass of controversial material.  At this period in his life our philosopher was convinced that he saw a great many things “clearly and vividly” as his phrase had it, and he defended rather obstinately, though sincerely, a philosophic system encumbered with inconsistencies.

            DesCartes’ personal appearance may be judged from the portrait by Hals now in the Louvre, which is well reproduced, among other places, in Bayliss’ “General Physiology”.  Mies Haldane who had studied this portrait describes the man as follows: --

            “His height was under the ordinary, and his figure rather slight and well formed, although the head is said to have been large in proportion to his body.  His forehead, as may be seen, was prominent, but the hair grew down upon it almost to the eyebrows.  His complexion, as he tells us himself, was pale in youth, but in Holland he gained some colour, though he lost this before the end.  On his cheek he had, somewhat like another great man, a wart or pimple which, though occasionally removed, always grew again.  The lower lip projected a little, the nose was rather prominent, and the eyes were dark grey.  His expression was said to have been agreeable, though this does not strike one in the portraits, and he had the power of retaining his self-control, and maintaining his serenity even in course of dispute.  His voice was pleasant, but he could not carry on a long discourse without interruption because of a slight weakness in the chest.  His hair and eyebrows were somewhat black, and the beard, worn in French fashion, was not quite as dark; he began, however, to turn grey at forty, and soon afterwards took to wigs, “four of which were found after his death”.  The wig he thought most beneficial to health; he was particular about his headdress being neat, and he had his wigs made in Paris, and of a colour as much as possible like his own hair; he begs Picot on one occasion to see that the black is “mingled with a few grey hairs”.

            Of a philosophical bachelor it is natural to inquire as to his views regarding the opposite sex.  Not much is known of his love affairs.  Traditions of a childish admiration for a “squint-eyed” girl have it that this defect was always mentally associated with beauty throughout the philosopher’s later life.  A lady of “birth and merit” in whom he was interested about the year 1625, withdrew her encouragement of his advances when he told her that “no beauty was comparable to that of truth” and declared further to a company of young gallants that “his own experiences --- not to say the refinement of his taste --- led him to declare that a beautiful woman, a good book and a perfect preacher were the things most impossible to discover in the world.”  This lady, however, delighted to tell how he disarmed a rival lover who attacked on the Orleans road in company with herself and other ladies.  The offender’s sword was returned with the remark that he owed his life to the lady rather than to his own prowess.

            In the year of his publication of the Treatise on the Development of the Fetus, a woman known only as Helene bore him, out of wedlock, a daughter, Francine, to whom he became tenderly attached and whose death a the age of six was probably the greatest sorrow of his life.

            The remarkable Platonic friendships developed much later in life.  A lively philosophical correspondence sprang up with the Princess Elisabeth of the Palatine and Bohemia, who was the granddaughter of James I and aunt of George I of England.  To her he dedicated his riper philosophical book, the “Principles”.  The Princess Elizabeth appears to have criticized his writings intelligently and to have gained from his friendship and philosophical advice, much solace in her rather unhappy and melancholic existence.  For her he wrote a remarkable ethical treatise on “The Passions of the Mind”.  This contains the statement:  “Nullam tam enbecillem ease animam, quae non posit, cum bene dirigitur, acquirere potestatem absolutam in passions suas”.  DesCartes was also acquainted with Elizabeth’s intimate friend, Anna Maria Schurmann, a prodigy of learning.

            The last year of DesCartes’ life was spent at the court of Queen Christine of Sweden, aged twenty-three.  She persuaded him to remove to Stockholm where an unusually rigorous winter brought DesCartes’ career to an untimely end.   Not a small part of the blame has been attached to her Majesty who compelled her philosopher to journey frequently to her library for an hour of instruction at five in the morning.  To a not too robust southerner who had maintained a lifelong habit of rising at about noon, this was inconsiderate to the breaking point.  Queen Christine, however, performed a real service to posterity in making DesCartes arrange his papers, which had gradually achieved a state of great confusion.  He was instrumental in helping the Queen establish an Academy of savants.

            One Francis Gribble published an article about fourteen years ago, entitled “DesCartes and the Princesses” which begins, “When our philosophical researches reveal the spectacle of two ladies contending for the sole possession of one philosopher, there are certain fairly warrantable inferences.”  He goes on to state that Kant was readily suffered to take his daily walk without a female hanging on his arm, while Herbert Spencer was permitted without any coquettish remonstrance to stuff his ears with cotton wool that his meditations might not be disturbed by the babble of the lady boarders at the dinner table.

            He describes DesCartes as “attired for his journey to Stockholm as if for conquest in other fields than those of intellectual strife.  A friend who saw him off was much impressed by the magnificence of his appearance and apparel; his carefully curled wig, his pointed shoes, and his richly embroidered gloves, his easy air of a polished man of the world.”  Even the pilot of the vessel is said to have observed to Queen Christine, “Madame, it is not a mere man that I bring you, it is a demi-god.”  DesCartes’ biographers as a whole do not seem to regard theses reports very seriously.

            DesCartes died at Stockholm of a respiratory infection on February 11, 1650.  A simple funeral was held according to the rites of the Catholic Church to which he had always remained loyal.  Later his remains, with great difficulties arising from various governmental formalities, were transported to Paris where they were reinterred with great magnificence in 1667.  In 1819, after a temporary sojourn in the court of the Louvre during the Revolutionary period, the body was moved to its present resting place at St. Germain-des-Pres.  DesCartes’ friend and posthumous editor, Clerselier, records as amongst his last words:  “My soul, thou has long been held captive; the hour has now come for thee to quit thy prison, to leave the trammels of this body; suffer then, this separation with joy and courage”