Accordingly, in May 1617, Descartes set out for the Netherlands and took service in the army of Prince Maurice of Orange.
At Rennes Descartes found little to interest him; and, after he had visited the maternal estate of which his father now put him in possession, he went to Paris, where he found the Rosicrucians the topic of the hour, and heard himself credited with partnership in their secrets.
RENE DESCARTES (1596-1650), French philosopher, was born at La Haye, in Touraine, midway between Tours and Poitiers, on the 31st of March 1596, and died at Stockholm on the 1th of February 1650.
Joachim Descartes, his father, having purchased a commission as counsellor in the parlement of Rennes, introduced the family into that demi-noblesse of the robe which, between the bourgeoisie and the high nobility, maintained a lofty rank in French society.
The withdrawal of Mersenne in 1614 to a post in the provinces was the signal for Descartes to abandon social life and shut himself up for nearly two years in a secluded house of the faubourg St Germain.
During the leisure thus arising, Descartes one day had his attention drawn to a placard in the Dutch tongue; as the language, of which he never became perfectly master, was then strange to him, he asked a bystander to interpret it into either French or Latin.
On the death of this general Descartes quitted the imperial service, and in July 1621 began a peaceful tour through Moravia, the borders of Poland, Pomerania, Brandenburg, Holstein and Friesland, from which he reappeared in February 1622 in Belgium, and betook himself directly to his father's home at Rennes in Brittany.
Towards the end of the year Descartes was on his way to Italy.
For an instant Descartes seems to have concurred in the plan of purchasing a post at Chatellerault, but he gave up the idea, and settled in Paris (June 1625), in the quarter where he had sought seclusion before.
Till 1649 Descartes lived in Holland.
But when Descartes arrived, he found Paris rent asunder by the civil war of the Fronde.
It is to her that the Principles of Philosophy were dedicated; and in her alone, according to Descartes, were united those generally separated talents for metaphysics and for mathematics which are so characteristically co-operative in the Cartesian system.
And yet, though Rembrandt's " Nightwatch " is dated the very year after the publication of the Meditations, not a word in Descartes breathes of any work of art or historical learning.
Descartes was not in any strict sense a reader.
The science of Descartes was physics in all its branches, but especially as applied to physiology.
Such then was the work that Descartes had in view in Holland.
In 1636 Descartes had resolved to publish some specimens of the fruits of his method, and some general observations on its 7 lb.
In 1644 it appeared in a Latin version, revised by Descartes, as Specimina philosophica.
The dispute on the latter point between Fermat and Descartes was continued, even after the philosopher's death, as late as 1662.
Only survived five years at Utrecht, and it was reserved for Heinrich Regius (van Roy) - who in 1638 had been appointed to the new chair of botany and theoretical medicine at Utrecht, and who visited Descartes at Egmond in order more thoroughly to learn his views - to throw down the gauntlet to the adherents of the old methods.
As yet Descartes was not directly attacked.
Voet now issued, under the name of Martin Schoock, one of his pupils, a pamphlet with the title of Methodus novae philosophiae Renati Descartes, in which atheism and infidelity were openly declared to be the effect of the new teaching.
Descartes replied to Vat directly in a letter, published at Amsterdam in 1643.
What might have happened we cannot tell; but Descartes threw himself on the protection of the French ambassador and the prince of Orange, and the city magistrates, from whom he vainly demanded satisfaction in a dignified letter,2 were snubbed by their superiors.
In the Discourse of Method Descartes had sketched the main points in his new views, with a mental autobiography which might explain their origin, and with some suggestions of as to their applications.
In 1644 the third great work of Descartes, the Principia philosophiae, appeared at Amsterdam.
It was about 1648 that Descartes lost his friends Mersenne and Mydorge by death.
The ambassador recovered, but Descartes fell a victim to the same disease, inflammation of the lungs.
Descartes never married, and had little of the amorous in his temperament.
Descartes accepted the philosophic mission, and in the spring of 1629 he settled in Holland.
Descartes was not disposed to be a martyr; he had a sincere respect for the church, and had no wish to begin an open conflict with established doctrines.
Undoubtedly, says Descartes, the world was in the beginning created in all its perfection.
When Descartes complained to the authorities of this unfair treatment, 4 the only reply was an order by which all mention of the name of Cartesianism, whether favourable or adverse, was forbidden in the university.
Civility, and the name of Descartes was no longer proscribed.
Through Chanut, with whom she was on terms of familiarity, she came to hear of Descartes, and a correspondence which the latter nominally carried on with the ambassador was in reality intended for the eyes of the queen.
With Descartes the use of exponents as now employed for denoting the powers of a quantity becomes systematic; and without some such step by which the homogeneity of successive powers is at once recognized, the binomial theorem could scarcely have been detected.
Thus Descartes gave to modern geometry that abstract and general character in which consists its superiority to the geometry of the ancients.
In another question connected with this, the problem of drawing tangents to any curve, Descartes was drawn into a controversy with Pierre (de) Fermat (1601-1663), Gilles Persone de Roberval (1602-1675), and Girard Desargues (1593-1661).
Fermat and Descartes agreed in regarding the tangent to a curve as a secant of that curve with the two points of intersection coinciding, while Roberval regarded it as the direction of the composite movement by which the curve can be described.
In pure algebra Descartes expounded and illustrated the general methods of solving equations up to those of the fourth degree (and believed that his method could go beyond), stated the law which connects the positive and negative roots of an equation with the changes of sign in the consecutive terms, and introduced the method of indeterminate coefficients for the solution of equations.'
The Geometry of Descartes, unlike the other parts of his essays, is not easy reading.
Descartes laid down the lines on which modern philosophy and science were to build.
The very moment when we begin to think, says Descartes, when we cease to be merely receptive, when we draw back and fix our attention on any point whatever of our belief, - that moment doubt begins.
The remedy proposed by Descartes is (while not neglecting our duties to others, ourselves and God) to let doubt range unchecked through the whole fabric of our customary convictions.
At this point Gassendi arrested Descartes and addressed his objections to him as pure intelligence, - O mens!
The God of Descartes is not merely the creator of the material universe; he is also the father of all truth in the intellectual world.
To attach a clear and definite meaning to the Cartesian doctrine of God, to show how much of it comes from the Christian theology and how much from the logic of idealism, how far the conception of a personal being as creator and preserver mingles with the pantheistic conception of an infinite and perfect something which is all in all, would be to go beyond Descartes and to ask for a solution of difficulties of which he was 1 Ouvres, vi.
Every moment one expects to find Descartes saying with Hobbes that man's thought has created God, or with Spinoza and Malebranche that it is God who really thinks in the apparent thought of man.
In disgust, Descartes started for the west to take part in the siege of La Rochelle, and entered the city with the troops (October 1628).
An invitation to the Swedish court was urged upon Descartes, and after much hesitation accepted; a vessel of the royal navy was ordered to wait upon him, and in September 1649 he left Egmond for the north.
Wanted Descartes to draw up a code for a proposed academy of the sciences, and to give her an hour of philosophic instruction every morning at five.
His friend Chanut fell dangerously ill; and Descartes, who devoted himself to attend in the sick-room, was obliged to issue from it every morning in the chill northern air of January, and spend an hour in the palace library.