Popular Science Monthly/Volume 37/October 1890/Sketch of Rene Descartes

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Popular Science Monthly Volume 37 October 1890  (1890) 
Sketch of Rene Descartes
 
PSM V37 D740 Rene Descartes.jpg

RENÉ DESCARTES.


SKETCH OF RENÉ DESCARTES.

PROF. HUXLEY, comparing the thoughts of men to the leaves, flowers, and fruit upon the branches of a few great stems bearing the names of the half-dozen men of strongest and clearest intellect, is of the opinion that "the thinker who more than any other stands in the relation of such a stem toward the philosophy and the science of the modern world is Rend Descartes. I mean," he adds, "that if you lay hold of any characteristic product of modern ways of thinking, either in the region of philosophy or in that of science, you find the spirit of that thought, if not its form, to have been present in the mind of the great Frenchman."

The London Spectator, reviewing Prof. Mahaffy's life of the philosopher, regards him as presenting the spectacle of a twofold life. "He was a man of society; he was a philosopher — the two were so completely distinct that they never came into collision. On the one side, he was inflexible, a pillar of intellect never deviating by a hair-breadth from rigid perpendicularity; on the other, he was all things to all men. For his intellect, the law was rejection of authority, assertion of absolute freedom; for the rest of him — for the man, distinguished from the philosopher — the law was courteous compliance all round."

René Descartes was born at La Haye, Touraine, France, March 31, 1596, and died in Stockholm, Sweden, February 11, 1650. He was the second son and third child of Joachim Descartes, who, having done some military service, had purchased a commission that gave him a place in the demi-noblesse. He inherited from his mother, who died at his birth, a feeble constitution, the marks of which he bore through life, and by reason of which the doctors predicted that he would die young; was baptized and brought up in the Roman Catholic faith; and betrayed from early infancy an insatiable curiosity and a disposition to inquire into the causes of things, which led his father to call him his philosopher. At eight years of age he was sent to the College of La Flêche, of the Jesuits, where he was remarked for his studious habits and the rapid progress he made in the knowledge of the ancients and in history. His delicate health seems to have contributed to his advance in scholarship, inclining him more to study than children of robust constitutions, and securing his exemption from morning duties, whereby he acquired the habit of meditating in bed. In that position a great part of the real work of his life was done. He accounted for his fondness for books by suggesting that the reading of good books was like a conversation with the brightest men of past times, but superior to ordinary conversation because the speakers presented only their best thoughts.

Besides the text-books of the school, he was fond of reading such books as treated of curious and rare knowledge, and he had a high esteem for eloquence and poetry as gifts of genius rather than fruits of study. Those who can give clear and forcible expression to their thoughts, he said, though they spoke in Bas Breton and had never learned rhetoric, could always exercise the most persuasive power ; and those who have the most pleasant fancies, and can express them most gracefully and with pertinent illustration, will not fail to be the best poets, though they have never studied the poetic art.

As the breadth of his knowledge enlarged, he grew more disposed to estimate the value of what he studied by its capacity of being made useful in life. He perceived the deficiencies of the logic and morals and of the physics and metaphysics that were taught in the college, and gained an increasing appreciation of the merits and beauty of the mathematical sciences. One of his first steps after leaving the college, he informs us in his Discourse on Method, was to discard his books, with all that he had learned that was uncertain, and to admit thenceforth only what seemed to have been demonstrated by reason and experiment. He therefore framed the method of examination and doubt, which, although he failed in very many instances to be true to it, has since become the great principle of positive science. He did not, however, he says, " imitate the skeptics, who doubt only for doubling's sake, and pretend to be always undecided; on the contrary, my whole intention was to arrive at certainty, and to dig away the drift and the sand until I reached the rock or the clay beneath."

After leaving the college, at the age of sixteen, he returned to his father, and in the next year went to Paris to participate in the social life of the capital and continue his studies. He renewed his school-day friendship with Marin Mersenne, now become Père Mersenne, of the Minim Friars, forming what proved to be a lasting alliance, and became associated with Claude Mydorge, one of the foremost mathematicians of France. Giving up the social side of his life, he withdrew for retirement and study to a secluded quarter. There is reason to believe that he made at this time some of his important geometrical studies, but he was not ready to publish them. A military career afforded at this age the most feasible means of getting the broadest views of life, and Descartes, in May, 1617, when twenty-one years of age, set out for the Netherlands and entered the service of Prince Maurice of Orange. Two years later he joined the forces of the Duke of Bavaria in the war between the house of Austria and the Protestant princes. While in garrison at Breda, he saw one day a placard in Flemish to which the attention of a considerable crowd had been attracted. It was the statement of a mathematical problem, to which the author, after the fashion of the times, invited solutions. Not understanding the language in which it was written, Descartes asked one of the bystanders to translate it to him. This man was Beeckman, Principal of the College of Dort, himself a mathematician. Surprised to find a young soldier interested in such a matter, Beeckman explained the terms of the challenge with his most learned air. Descartes said at once that he would solve the problem, and brought the solution to Beeckman on the next day, having mastered it in less than an hour. The winter of 1619 was spent in quarters at Neuburg, on the Danube, to a large extent in study, and was, according to Dr. William Wallace, in the Encyclopaedia Britannica, the critical period of Descartes's life. "Here, in his warm room, he indulged those meditations which afterward led to the Discourse on Method. It was here that, on the eve of St. Martin's day, he 'was filled with enthusiasm, and discovered the foundations of a marvelous science.' He retired to rest with anxious thoughts of his future career, which haunted him through the night in three dreams, that left a deep impression on his mind. ' Next day,' he continues, 'I began to understand the first principles of my marvelous discovery.'" In the next year he sought out the Rosicrucians, to obtain some knowledge of their supposed mystical wisdom, but without success. Descartes retired from military life upon the defeat and death of Count Bucquoy at the hands of Bethlen Gabor's revolted Hungarians in 1621.

During his career in the army, Descartes composed a Latin treatise on music, which he intrusted to Beeckman. It was surreptitiously copied, and was published without the knowledge of the author in 1618. It seems to have been considerably successful, and was reprinted several times and translated into English and French. But Beeckman's treachery cost him Descartes's friendship. Among other writings of this period, unpublished or lost, but mentioned in the catalogue prepared by Chanut on the order of Queen Christina of Sweden, are General Considerations on Science; a fragment on Algebra; Democritia, or Fugitive Thoughts; Experiments, or a Collection of Observations; and a collection of mathematical speculations entitled Parnassus. Descartes continued his travels in a private way, having in view, as he expressed his purpose, to look into the courts of princes, to become acquainted with men of different humors and different conditions, to inform himself concerning the natural products of different climates and the various civil usages and customs observed among different peoples; and to seek in the great book of the world knowledge that could not be acquired elsewhere. From his observations he gained the great advantages of learning to believe nothing lightly, and not to hold obstinately to the things which example and habit had accustomed him to believe. He visited Holland, France, Italy, Switzerland, the Tyrol, Venice, and Rome. At Venice he witnessed the ceremony of the wedding of the Doge with the Adriatic. He made a pilgrimage to the shrine of Loretto.

Returning to France, Descartes entertained for a time the thought of purchasing a position as lieutenant-general of the province, at Chatellerault, but the legal chicanery connected with the office was not to his taste, and he gave up the scheme. He then took lodgings in Paris, and lived in the style of a modest gentleman at ease. He gathered a few friends around him, among whom were Mersenne and Mydorge, who were interested in the problems of the refraction of light; and together they experimented in the grinding of lenses. With others who came to witness the experiments, the house became a kind of academy, and too busy a resort to favor Descartes's studies. Meetings of literary men and students had become common in Paris, the more important ones being held with the Papal nuncio and Cardinal Richelieu. Descartes, urged by his friends, attended them frequently. He had, in his reflections on the choice of a position, become confirmed in the thought that he should not confine himself to any business, but should devote his life to the cultivation of the reason, and to advancement by every possible means in the knowledge of the truth according to the method which he had prescribed. At one of the meetings Cardinal de Bdrulle was struck by a remark of Descartes's that the true art of memory was not to be gained by technical devices, but by a philosophical appreciation of things. He was thereby prompted to urge upon him a plan of life in almost exact accord with his conviction.

His associations in Paris, with their distractions not being favorable to the close attention which he sought to exercise to qualify himself for the execution of his purpose, Descartes determined to retire to some place where he could be alone and could pursue his studies untrammeled. He went to Holland, where he found variety and congenial retreats during the period from 1629 to 1649 in thirteen different places, and where he composed or revised most of his works. In the choice of these residences he seems to have been influenced, according to Mr. Wallace, by the two considerations of the neighborhood of a university or college, and the amenities of the situation. He appears to have also had a decidedly religious inclination. He found Franeker, the seat of a university, very agreeable, because it afforded him opportunity for attending mass, and gave him freedom in the religious exercises on which his attention was apparently most fixed during the first nine months of his residence. He wrote from Amsterdam to Balzac, who had expostulated with him for having withdrawn himself from the world : " In this great city where I am, there being no one except myself who is not in trade, every one is so intent on his specnlations that I might stay here all my life without being seen by any one. I walk out every day amid the confusion of a great people with as much freedom and peace as you could have in your garden walks, and I pay no more attention to the men who pass before my eyes than you would to the trees in your woods and the animals feeding there. Even the noise they make works no more interruption to my thoughts than would the rumbling of a brook." He resumed his studies in dioptrics. Observations on parhelia gave the origin to his treatise on Meteors. He entered with great ardor upon the study of medicine and anatomy, and visited the butchers' shops every day to witness the slaughter of animals, of which he brought parts home to his rooms to be dissected at his leisure. His correspondence with Pere Mersenne abounded in mathematical problems which the two exchanged with each other. He studied astronomy and composed his Traite' du Monde, in which he avowed the doctrine of the motion of the earth. On learning, however, of the condemnation of Galileo, he suppressed this book, saying, in a letter to Père Mersenne : " All the things I have explained, although I believe them to be supported by very certain and very evident demonstrations, I would not for the world maintain against the authority of the Church. . . . My desire to live in quiet and continue the retired life I have begun makes me more content to see myself delivered from the fear of having gained more fame than I wished for by my writing, than sorry for having lost the time and trouble that I have taken in composing it."

Descartes made three visits to France during his residence in Holland. The first was in 1644, to settle family affairs after the death of his father in 1640; the second was signalized by an award to him of a pension secured by Cardinal Mazarin of three thousand francs, in consideration of the advantages which his investigations had conferred upon mankind, and to aid him in continuing them ; the third visit ended in disappointment, for the substantial results anticipated from it were nullified by the breaking out of the civil war of the Fronde. During the second of these visits he is said to have met Pascal, and suggested to him the thought of experimenting on the weight of the air. A visit was made to England for the investigation of magnetic phenomena, and in 1634 Descartes took an excursion into Denmark.

A controversy in 1638 with Fermat concerning that author's book on Maxima and Minima, and on tangents, engaged the friends of both parties, and resulted in a friendship between the chiefs. Descartes had other discussions — with Petit on dioptrics, Morin on light, Beaugrand on geostatics, Roberval on the line described by a nail on the outside of a wheel in motion, and with Voet, Professor of Theology at Utrecht. The last controversy, which was brought on by Voet's criticisms of the indiscreet utterances of Descartes's disciple, Regius, resulted in Descartes being summoned before the magistrates of Utrecht on charges of irreligion and slander. He escaped the threatened prosecution by claiming the protection of the French ambassador and the Prince of Orange. An order forbidding all mention of the name of Cartesianism at the University of Leyden was likewise annulled by direction of the Prince of Orange.

Queen Christina of Sweden, interested in her way, although she was not yet twenty years old, in matters of literature and philosophy, having heard of the great fame of Descartes, conceived a desire to become acquainted with him. He was drawn into a correspondence with her through Chanut, the French ambassador to Sweden, to whom he sent a dissertation on Love, which was intended for her. He followed this with an essay on the Chief Good, addressed directly to the queen. Finally, she invited Descartes to go to Sweden and give her lessons in philosophy. Descartes acceded to the request after considerable hesitation. He reached Stockholm in October, 1649. The queen was very exacting in her demands on the philosopher, and required, among other things, that he attend upon her every morning at five o'clock. The hardship of this duty, which did violence to his life-long habit of lingering in bed, with other incidents of his life at the Swedish capital, combined with the rigor of the winter climate, were too much for Descartes, and entailed upon him a pneumonia, from which he died.

The written works of Descartes were collected and published in Latin in 1670-'83. A selection from them was published in Paris in 1843, and a collection of his moral and philosophical works in 1855.

The earliest work was the Discourse on the Method of Reasoning Well and Seeking the Truth in Science, which, besides the exposition of general principles, according to the description in the title, contains treatises on Dioptrics, Meteors, and Geometry, the general scope of which is indicated by their titles. The central propositions of the whole Discourse, according to Prof. Huxley, are: "There is a path that leads to truth so surely that any one who follows it must needs reach the goal, whether his capacity be great or small. And there is one guiding rule by which a man may always find this path and keep himself from straying when he has found it. This golden rule is, Give unqualified assent to no proposition but those the truth of which is so clear and distinct that they can not be doubted." Descartes attached less importance to the geometrical and mathematical methods of which he was the inventor than to his moral and metaphysical speculations. But, while the latter have been sifted and riddled in discussion, and have suffered under the revolutions of thought, the mathematical principles he established and the methods he introduced remain. In geometry he gave demonstrations of general principles, under which solutions adapted to one problem could be applied to all like it. In algebra, for the old clumsy notation and nomenclature, always suggesting material relations, he substituted the beautiful, convenient system, purely abstract, by the aid of which that branch of the science has marched to almost universal application and perfection. And in the application of algebra to geometry, he introduced the method of abscissas and ordinates, by means of which any curve and any condition of form can be computed by a process as beautiful as it is direct.

The Meditations on the First Philosophy, which appeared in manuscript in 1640, consists of six parts, in the first of which the author expounds his philosophy of doubt; in the second, he reaches the certainty of his own being, through the use of his famous maxim, cogito, ergo sum (I think, therefore I am); in the third, he deduces an argument to prove the existence of God from the idea of an infinite and sovereignly perfect being; in the fourth, he draws a distinction between speculative reasoning, for which the light of nature is sufficient, and doctrines of faith and the conduct of life, which rest on another foundation; in the fifth, he explains the corporeal nature, and brings forward another argument for the existence of God; and in the sixth he treats of the distinctions between intellect and imagination, the difference yet intimate connection of soul and body, errors of the senses and the means of avoiding them, and the reasons upon which we can conclude concerning the existence of material things, which he, however, regarded as inferior to the evidence on which we predicate the existence of God and the soul. The book in this form was submitted to the criticisms of a number of distinguished students, whose objections were printed and bound with the main treatise when it was published in 1641, and with them the replies of the author, considerably swelling the bulk of the volume.

The Principles of Philosophy, 1644, contained an exposition of the principles of knowledge as developed in the Meditations; an explanation of the primary laws of nature, the properties of matter, space, motion, etc. ; the system of the world, the sky, and celestial bodies ; and a treatise on the Earth. The statement of the three laws of nature, the seven secondary laws of impact (which are pronounced by later science to a large extent incorrect), and the famous theory of Vortices, by which Descartes attempted to account for the structure of the universe, are contained in this work. The first of the three laws affirms that every body, so far as it is unaffected by extraneous causes, always perseveres in the same state of motion or rest; and the second that simple or elementary motion is always in a straight line. "These doctrines of inertia, and of the composite character of curvilinear motion," says Mr. Wallace, "were scarcely apprehended even by Kepler or Galileo; but they follow naturally from the geometrical analysis of Descartes." He taught that extended matter has no limits to its extent, though the power of God has divided it by lines discriminating its parts in endless ways. He denied the possibility of a vacuum, and the existence of atoms or ultimate particles, and regarded matter as uniform in character throughout the universe  —  all of which views are consistent with what may be logically deduced from the results of the latest investigations. In the universe packed with matter, no particle can move unless all the others move too. Hence we have universal motion, taking the form of "a host of more or less circular movements, and of vortices or whirlpools of material particles, varying in size and velocity." These vortices, which were supposed to give rise to three kinds of matter and to the phenomena of radiating light, were made to account for the existence and motions of all the stars and systems, the sun and planets, and the earth. Descartes applied his vorticellar theory not only to all the phenomena of physics, but also to those of organic life, including that in animals and man; whence he ventured to show that man and the animals are really machines, with the single difference that man has a rational soul, while the animals have not. In the Treatise on Man and the Formation of the Foetus, which was published after his death, Descartes expounded the doctrine of animal spirits. Other works are the Treatise on the Passions of the Soul, which was translated into French for Madame Elizabeth, Princess Palatine; and the Rules for the Direction of the Mind, a posthumous work. Descartes was never married, but he is believed to have had a natural daughter, Francine, who died when she was five years old. He is described as having been " a little man, with a large head, projecting brow, prominent nose, and eyes wide apart, with hair coming down almost to his eyebrows," and feeble voice, and as usually dressed in black.

On his death, Queen Christina wanted him buried with the kings of Sweden; but Chanut, who is supposed to have carried out his wishes, had his body modestly interred in the cemetery of the Orphans' Hospital, where Catholic foreigners were usually buried. Thence his remains were a few years afterward transferred to France, where, after several changes, they were finally deposited, in 1819, in the Church of Saint Germain des Prés.