Its life French philosopher. René Descartes was born on on March 31st, 1596, according to the tradition in $the Hague (today Descartes, Indre-et-Loire) and, actually, with the hamlet of Sibyllière (between Châtellerault and $the Hague), where his/her mother had had to stop. Descartes is resulting from a family of gentlemen from Poitou.
From 1604 to 1612, he was pupil of the Jesuits, with the college of the Arrow, where he studied the old letters, the philosophy of Aristote, and rained himself especially with mathematics. From 1618 to 1629, it spent its time “to travel, seeing courses and armies”; it also dealt of science and philosophy.
Its vocation of philosopher set in November 1619 definitively: locked up in its stove - a part heated by this apparatus - around Ulm, he discovered with enthusiasm the bases of “an admirable science”. Its prophetic dreams, its wish of a pilgrimage with Our-Lady-of-Lorette and its adhesion at the company of the Rosicrucian brotherhood testify to a mystical crisis, is a prelude to with a true intellectual revolution.
In 1629, Descartes took refuge in Holland, to develop a “new philosophy”, which he sought to propagate in broad circles. Its stay was stopped only by three short voyages in France (in 1644.1647 and 1648); during the second, he advised with the Pascal young person to carry out experiments on the vacuum. In spite of its greatest caution - it gave up, after the judgment of Galileo (1633), to publish his Treaty of the world, which will appear only in 1664, Descartes undergoes to them violent attacks of the partisans of Aristote, the French Jesuits and the Protestant ministers of Holland: in 1642, the senate of Utrecht prohibits the teaching of the Cartesian doctrines, “initially because it is new, then because it diverts the youth of the old woman and healthy philosophy.”
In 1649, Descartes left for Sweden, with the invitation of the Christine queen. Suffering from the rigor of the climate, he died in Stockholm, of a pulmonary congestion.
Its work
Descartes published, in 1637, in Leyde, the Discourse on Method, which is at the same time the narration of its own intellectual route and the proclamation, written in French, of the Cartesian revolution. After this work which found a broad audience, Descartes returned to the “technical” language of philosophy, Latin, in Meditationes of PRIMA philosophia (1641), intended for the theologists, and Principia philosophiae (1644), intended for teaching. Then, undoubtedly hoping to convince “honest people more easily” than the “learned ones”, it made appear, in 1647, the French translation of the Meditations and that of the Principles. Its last work, the Treaty of Passions, was published in 1649.
Other works were published only after its death: Treaty of the world (written in 1634); rules for the direction of the spirit (unfinished opuscule, written in Latin around 1628); is added to it an abundant correspondence, for example the letters with the Elisabeth princess, on morals, or those with the Mersenne father, who was the major intermediate between Descartes and the scientists and philosophers of his time.
One can arbitrarily divide the work of Descartes into various parts: philosophy, metaphysics, physics, biology and finally morals. In each one of them, the method applied by Descartes is identical: it is based on the doubt, which must make it possible to reach the truth.
Object and method of philosophy
Opening the way with modern philosophy, Descartes made ideas the true object of philosophical knowledge. It is by them, he affirms, that the spirit knows the things: admittedly, the ideas are only in the spirit, but they have the property to represent the things which are out of the spirit.
Conquest of the truth
Philosophy is the study of wisdom. As the conquistadores sprang towards unknown grounds, Descartes boldly takes the road which must lead it to new truths, with the universal truth. To devote its life to the truth is for him best occupations, worthiest of the man. At the end of its studies, it had been embarrassed doubts and errors; admittedly, mathematics had allured it by the obviousness of their reasons, but philosophy and sciences which depend on it do not reach, estimates Descartes, who the probable one and are not consequently of any utility.
This speculative philosophy must yield the place to a practical philosophy, which will enable us to use the natural forces and thus “to return to us as Masters and owners of nature”. Then the men will be able to enjoy, without any sorrow, of the fruits of the ground and all the conveniences which meet there; they will be able to preserve health and “to perhaps even exempt weakening of old age”; finally, the spirit depends so extremely on the temperament which they will become, thanks to medicine, wiser and more skilful.
Thus, the wisdom, whose philosophy is the study, is not other than the “perfect knowledge of all the things which the man can know, so much for the conduit of its life than for the conservation of its health and the invention of all arts”. “All philosophy is as a tree of which the roots are metaphysics, the trunk is principal physics, and the three branches medicine, mechanics and morals.”
According to Descartes, “the good sense is the thing of the world best divided”, as the sentence proclaims it which opens the Discourse on Method. How to arrive at the truth? By the “good sense” or the reason, which distinguishes the man from the animal, and which is precisely “the power to judge well, and to distinguish truth from with the forgery”. The reason comprises two faculties: intuition, “natural light”, “intellectual instinct” which seize its object immediately, and the deduction by which “we understand all the things which are the consequence of some others”.
The mathematician, for example, knows by intuition these “simple natures” which are the figure, size, the place, time, etc; or many indubitable truths like: a sphere has only one surface; or finally the bond between two truths: between 1 + 3 = 4.2 + 2 = 4, on the one hand, 1 + 3 = 2 + 2 on the other hand. Mathematics shows us also how much the deduction is different from the syllogism; to the sterility of the syllogism, which is rather used to teach that to learn, is indeed opposed the fruitfulness of the deduction, which determines the nature of an unknown thing by means of its relations with the known things: thus, one calculates a term of a progression, or the unknown factor of an equation.
Universal mathematics
The reason, however, is not the method; “because is not enough to have the good spirit, but the main thing is to apply it well”; the role of the method is to indicate how must take place the deduction, and how it is necessary to make use of the intuition. Here still, mathematics provides the model; their “long chains all of reasons, simple and easy”, lead us to think that “all the things, which can fall under knowledge from the men, between-are followed in same way”; let us add that, the method insisting in practice than in theory, the best means of learning it is systematically to apply it to the simplest cases: mathematics accustoms the spirit thus “to be fed of truths”.
But, so that the mathematical method can be wide with all the objects of knowledge, it must acquire initially, in its own field, a sufficient degree of general information. “Mathematics vulgar” - arithmetic, geometry, astronomy, music, optics -, which relates to particular sizes, it is necessary to release a “universal mathematics”, which considers the reports or proportions in general. However, by improving algebraic symbolism (employment of the letters and the exhibitors) and by looking further into the methods of resolution of the equations, Descartes makes algebra an instrument able to express the properties of the figures; synthesis of the algebra of Modern and the geometrical analysis of Old, analytical geometry represented in the language of the number the continuous variations of the space sizes; consequently, mathematics can study the movement, which is the gasoline of all the natural phenomena.
Four precepts
The Discourse on Method simplifies the logic, brought back to four fundamental precepts. “The first was not to never receive any thing for true, that I obviously did not know it to be such.” For the authority of Aristote, Descartes substitutes that of the reason, i.e. the free examination; admittedly, the intuition nor the deduction are not learned; what Descartes prescribes, it is to learn how to employ only they. The obviousness that they get consists in the clearness and the distinction of the ideas: an idea is clear when it is present and manifest with an attentive spirit; it is distinct when the spirit sees whether well what it contains that it necessarily distinguishes it from very other.
The complex concepts become clear and distinct when one reduces them to their elements. From where the second precept: “. to divide each difficulty which I would examine, in as many pieces as it could, and than it would be necessary for best solving”; thus the mathematician releases “simple natures” and the “absolute” of a problem, i.e. the last condition of his solution: he finds, for example, as many equations as of unknown lines. Inseparable from the second, the third precept is “to lead by order my thoughts, while starting with the simplest objects and easiest to know, to go up little by little, as by degrees, jusques with the knowledge of made up”; thus, Descartes, in his mathematical research, starts with simplest questions the “and most general” and triumphs at the end of several “which he had considered to be very difficult formerly”. Because it followed “the true order” and, moreover, “counted exactly all the circumstances” of what it sought, i.e. discovered all that was necessary and sufficient to solve the questions; if, for example, one wants to study the conic sections, it is necessary and it is enough that one takes account of the three possible cases: the plan which cuts the cone is perpendicular, parallel or oblique with its axis; such is, it seems, the direction of the last precept: “. to make everywhere so whole enumerations and reviews so general that I was ensured anything to omit”.
Physics and metaphysics
Considered as a whole, the Cartesian “method” is a method of pure reasoning, whose model is provided by the mathematical deduction. Let us specify that it will not be applied completely same manner to metaphysics and physics: on the one hand, indeed, one could not discover in metaphysics of quantitative reports; in addition, the experiment is essential in physics. Descartes physicist will make a place with the experimental method, as it further will be seen.
Metaphysics
We point out the image of the tree, of which the roots are metaphysics. Descartes follows the tradition, which wants that the principles of sciences all “are borrowed of philosophy”; he does this one, heard within the meaning of “philosophy first”, the base of physics.
To know the material world, it is necessary initially to know these immaterial realities that are the heart and God. Such a knowledge is with our range, if we succeed in raising our spirit “beyond the sensitive things”, if we do not confuse the understandable one with the conceivable one; the error of the scholastic was precisely to admit this maxim that “there is nothing in the understanding which firstly was not in the direction”, “where however it is certain that the ideas of God and the heart never were”.
The methodical doubt
Doubts which embarrassed it at its exit of the college, Descartes will extract the means of even arriving at the truth; he will indeed reject, like absolutely false, all it in what he can imagine the slightest doubt, in order to see whether it will not remain, after that, something in his credit which is entirely indubitable. Taking again the traditional arguments of skepticism, he calls upon the errors of the directions and the illusions of the dreams to reject any knowledge of significant origin, including the belief in the existence of the world.
Its pitiless critic does not save even any more mathematics. Isn't there, indeed, of the men who mistake while reasoning? With this argument of the Speech, in the Meditations, the extraordinary assumption of an enough powerful “evil genius is added” to change the truth at the moment even where I see it, and to make thus that I am mistaken when, for example, I add 2 and 3, or that I number sides of a square.
Such is this doubt pushed to the extreme, doubts “hyperbolic” from which only the maxims from a provisional morals and the truths of the faith escape: “because I cannot remain irresolute in my actions while the reason obliges me to be it in my judgments”; as for the revealed truths, they are out of discussion, since they exceed our intelligence.
But if mathematics is dubious, that becomes logic that one had drawn some? Does one have maintaining the right to apply the “method”, to regard as true the clear and distinct ideas? To read Descartes, one has initially the impression that this right remains, then one realizes that a guarantee is necessary for him.
The existence of the heart
While I doubt, while I think that all is false, it is necessary necessarily that me, who think it, would be something; “Cogito, ergo sum” (“I think, therefore I am”), such is the first truth, farm and ensured, that I have finally; the assertion of ego thinking the existence of the world being still a “problem” -, such is the first principle of philosophy.
The certainty of this principle resides, note it, in this: “I see very clearly that, to think, it is necessary to be”; I can thus generalize, and to take for rule “that the things which we design extremely clearly and extremely distinctly are all true”.
Gasoline of the heart
Another consequence results from Cogito: since I can doubt the material things and that the fact of my existence is implied in this doubt even, it is clear that I am “a substance of which all gasoline or nature is to only think and who, to be, does not need any place nor does not depend on any material thing. So that this me, i.e. the heart by which I am what I am, is entirely distinct from the body”. Guard should well be taken that it is there, not a deduction, but an intuitive observation, which is equivalent to “I think, I am, I seize myself while thinking”. “Thus” can make illusion with a spirit not prevented.
This radical separation operated by Descartes between the body and the heart, the wide substance and the thinking substance, would be understood with sorrow if one did not refer to physics. Philosophy scholastic explained the natural phenomena by “forms” similar to the heart; modern physics, on the contrary, looks at the matter like “inert” and explains the material facts by the material facts; from where the idea, natural at Descartes, to make heart and thought, expelled so to speak of the matter, a world except for; the physical mechanist being born required a spiritualistic metaphysics which was rigorously dualistic.
Considered in itself, the demonstration of the spirituality of the heart seems to us not very convincing today. What proves Cogito indeed? That I can clearly conceive the heart without the body; to pass from this distinction in the thought to a distinction in reality, it is necessary to be well persuaded that our clear ideas answer an objective reality. Descartes, however, when it treats physics, will feel the need to add to the reasoning of the evidence drawn from the experiment; the language nor the human activity cannot be imitated by machines, or the animals; one, consequently, is more been willing to admit that our heart is immaterial, and consequently - according to any probability - immortal.
The existence of God
The doubt is an imperfection; I see clearly, indeed, who it is a greater perfection to know than to doubt. But from where does this idea come me from perfect? It cannot come from me, which am an imperfect being; because the cause must have reality at least as much than its effect; the cause of the idea of perfect can be only the perfect being itself, i.e. God. It is a renewal of the proof of Anselme saint.
I admittedly do not know the way in which I had idea of God. Going up higher, I thus will seek which can be the author of my heart; it cannot be myself, because I would have given myself all the perfections of which I have the idea; thus the being which created me has all these perfections indeed: he is God.
Does this two complementary evidence seem too complicated? One can call upon another argument, more intuitive: the existence of God is understood in his gasoline, “in same way that it is understood in that of a triangle that its three angles are equal to two rights”; the existence, indeed, being a perfection, the perfect Being, which has all the perfections, has necessarily the existence.
That the existence thus “shown” either an existence in the thought, and not a real existence, it is what appears hardly doubtful (Kant will show the defect of the argument baptized by him “ontological”). The same idealism, the same identification of reality and the idea - had with the use of the mathematical method - is implied besides in the first proof, which rests on this postulate: the idea of perfect is itself something of perfect.
Gasoline of God
By proving God by the idea of perfect, “we know by the same means what it is, as far as allows it the weakness of our nature”. Thus, we see that it is infinite, eternal, immutable, all knowing, the Almighty, source of any kindness and truth, creator of all things. God is a purely spiritual being: because if it were composed of two natures, the intelligent one and the body one, it would depend on its elements, and any dependence is a defect and objection to perfection.
God is source of any kindness and truth: consequently, all our doubts disappear; our clear and distinct ideas are true, since they are real things which come from God. Consequently, according to the Meditations, the distinction of the heart and the body, which we conceive very clearly, becomes a “real” distinction; the Being the Almighty could not be misleading: the assumption of the “evil genius” disappears. But isn't there here a vicious circle, as objected it the Gassendi materialist? On the one hand, God exists because one has a clear idea of it; in addition, a clear idea is true because God exists. It seems well that, on this subject, Descartes did not give entirely satisfactory explanations for which is not idealistic.
The divine veracity ensures us in addition, not only of the value of the clear ideas, but of the objective existence of the world. We believe instinctively in this existence, and God could not want that this instinct mislays us. Not to tell the truth let us take guard however that the directions inform us strong evil, on the utility of the material things, but on their nature; significant qualities of a piece of wax change if the object becomes liquid or gas; only the reason, with its clear and distinct ideas, can know the material things.
For the theory scholastic, the truths which we reach here below are reflections of the true gasolines which we will contemplate in the divine understanding. For Descartes, it is permissible for us as of this life to know perfectly the true gasolines, the eternal truths, which are creatures of God. In this one, the understanding is subordinated to the will: “If God had wanted it, two and two would make five, and it would be virtuous to kill his brother.”
In possession of the first truths - without them, “an atheist cannot be a geometrician” -, we can deduce the principles from physics and the natural laws. However, because of the finitude of our understanding and the complexity of nature, it is advisable to observe and analyze this one, by going up effects with the causes.
Physics
The work of the scientist
Genious mathematician, Descartes is also one of the founders of physics. Less happy than Galileo in his research on the fall of the bodies, he triumphs in optics: he discovers, around 1626, the law of the refraction, then he makes progress the theory of the rainbow. On another ground, finally, he formulates with clearness our modern concept of work (1637).
Object and method of physics
Descartes did not only look further into particular questions of physics. He traversed, in the World and the Principles, the immense field of physics itself, chemistry, biology; the work of the scientist-philosopher - and either of the very short scientist - is with the remainder a curious mixture of brilliant intuitions and more or less arbitrary explanations.
Descartes is of agreement with Galileo, who “tries to examine the physical matters by mathematical reasons” and declares: “All my physics is other thing only geometry.” And the epitaph of Descartes known as: “Confronting the mysteries of nature with the laws of mathematics, Descartes conceived the daring hope to open with the same key the secrecies of the one and other.” The method will be thus deductive, starting from the principles provided by metaphysics and the reason (principles of conservation). Those are assumptions with the mathematical direction, bases of a construction of truths, and not of the conjectures or working hypotheses.
However, to distinguish the bodies which are on the Earth of an infinity of others which could be there, it is necessary to come “ahead of of the causes by the effects”, to institute experiments to decide between the various conceivable explanations, i.e. also compatible with the principles, while taking care not to interpret them so as to make them appear formed so that one initially supposed. The goal of the Discourse on Method, exposed in its last part, is to obtain the helps necessary to institute such experiments. Descartes makes more than to have a presentiment of the experimental method, insistent on to and from between the idea and the fact, and on their reciprocal action.
For the detail of the rules, Descartes returns to Bacon, after which it does not have anything any more to say. In fact, the width even of its intention led it to subordinate to the pure reasoning the experimental method which, except in the cases enumerated above - optical, work. -, generally remained as regards the theory.
Principles of physics
Like Galileo, Descartes adopts the vision copernician of the world: the man is not any more the end of creation, the Earth is not any more the center of the universe. Generally, it entirely rejects its philosophy the investigation into the final causes: it tries to find how, and not for what, the material things could be produced.
The gasoline of the material things is the extent, infinite space; a body is only one limited part of the extent; that is to say a body supposed in rest: another is known as moving if its position compared to the first is never the same one in various moments. With the extent and the movement, Descartes flatters itself to rebuild the world; can't one assimilate, on the whole, the effects of the natural bodies to those of the machines which the craftsmen make? The only difference is that “the pipes or springs which cause them. are usually too small to be perceived our directions”. Thus, “the rules of mechanics are the same ones as those of nature”.
All in all, Descartes thinks the matter according to two sciences which, at its time, are sufficiently advanced: mathematics and mechanics; consequently, he formulates the design mechanist of the science, which was to reign without question during more than two centuries; to bring back, indeed, the natural phenomena with measurable movements, it was to suggest with the scientists a working hypothesis which was only to be shown fertilizes, until one realizes that the mechanical movement, the simple change of place, is not the only species of change which actually occurs in the world.
In fact, the mechanism present at Descartes certain characters which are not essential for him. The only cause of the movement is the shock, whose action is instantaneous (the light, for example, crosses in one moment immense spaces of the skies). Any real movement is swirling (circular): there is no vacuum, indeed, since the extent merges with the matter; if thus a body pushes in front of him another body, this one pushes some another, and so on, until that which was behind the first, and which takes its place.
Shocks and swirls obey two great principles, both founded on divine immutability: inertia, and conservation of the momentum. The will of God, being absolute, could not change; God, consequently, could not want, at a certain moment, that it had there more movement in the world, with another less; by formulating this law (the momentum is defined by mv , and Leibniz will give principle of conservation a more exact expression, which itself will be corrected later), Descartes affirms by advance, in a brilliant intuition, the conservation of energy, which will be proven two centuries after him.
Genesis of the world
However, it cannot go until seeing in the movement an essential property of the matter, which is on the contrary “inert”. The movement comes from the outside, of an initial impulse communicated by God. This concession with theology will not appear sufficient to Pascal, who will write on this point: “I then to forgive in Descartes; he would have liked, in all his philosophy, to be able to pass itself from God; but it could not be prevented from making him give a flick, to put the world moving; after that, it does not have any more but to make of God.”
God, indeed, lets act nature according to the laws which it established; the chaos of which he is the author organizes then gradually. This diagram of creation is certainly in obvious dissension with the account of the Bible, according to which “as of the beginning, God. the world such as it returned was to be”; it rests, in any case, on an idea whose later development of science showed all the value: the nature of the material things “is much easier to conceive, when one sees them being born little by little in this kind, that when it is not considered them that done everything”.
By there, Descartes is led to certain assumptions whose range could not be neglected; more than one century before Kant and Laplace, it tries to explain the formation of the solar system; two hundred years before the theories transformists, it brings back the formation of the man - or more exactly of the human body - not to the divine intelligence, but to the “eternal laws of nature”.
Biology
We will not go into the details of Cartesian physics. Let us see only what she teaches us on the animals and the men.
The animals machines
Comparing the living matter to the raw material, and refusing with the animals the thought, Descartes compares the latter with the “automats, or moving machines, that the industry of the men can make”. Admittedly, the animals are pure machines, because they are unable to speak, with the full direction of the term; they testify more industry than us in some their actions, but in the manner of a clock, which measures time exactly; finally, if a heart were granted to them, it would be necessary to admit, or although it is immortal like the human heart, or although this one is mortal like the heart of the animals.
Functions of the human body
The reason is the only thing which distinguishes us from the animals. Because the human body is, him also, a machine. The movement of the heart and the arteries “as necessarily follows of the only provision of the bodies as one can see with the eye in the heart and of heat that one can there feel with the fingers, and of the nature of the blood that one can know by experiment, which makes that of a clock, force, situation and figure of its counterweights and its wheels”.
The other body functions are explained, they also, as continuations of this “fire without light” which burns continuously in the heart; for example, most agitated parts the “and most penetrating” of the blood heated by the heart compose the “animal spirits”, left very pure and very sharp flame which, circulating inside the nerves, comes to produce the movements of the members.
Double aspect of biology
If Descartes, in his biology, partly continues the scholastic by subordinating the experiment to the reasoning a priori, by preserving, in addition, certain whimsical concepts like those of cardiac fire or the animal spirits, as a whole, however, it makes work of innovator: it propagates the great discovery of Harvey, that of the blood circulation.
Besides he explains it - contrary to Harvey and contrary to the facts - by cardiac heat: the heart is not for him a pump, but a thermosiphon. It invites the physiologists to get rid of occult qualities (heart vegetative or sensitive, pulsific faculty, etc), and to discover the mechanical phenomena or physics which occurs in the living matter; is it need to add that this program could not be filled by only one man, especially at a time when the instruments necessary to the observation, the microscope in particular, did not exist yet?
Morals
Psychophysiology
“Highest and most perfect morals” presupposes a whole knowledge of other sciences; doesn't it require, indeed, a whole knowledge of the man and reports which it maintains with the world and God?
Union of the heart and the body
However, metaphysics makes known to us the heart, and the physique the human body; but we could not understand the feelings and the appetites, to reconstitute the “true man”, if we do not suppose that the heart is united and linked narrowly with the body; thus the body acts on the heart in the feeling and passion, and the heart on the body in the voluntary act. Obscure design, certainly, since there is nothing commun run between their two natures; only the absolute power of God can explain this union.
The heart is related to the body via the pineal body. This one is driven by the “animal spirits” which are projected towards it, when the external objects strike our directions; these movements of gland can reproduce besides, in the absence of any object, in consequence of the traces which the spirits left in the brain.
Passions and will
In the last years of his life, Descartes relegates to the second plan speculative metaphysics and sciences to explore more at bottom the sphere of the union of the heart and the body and to thus outline a morals which does not have undoubtedly the form nor even coherence that it had conceived for it. The letters of Descartes to the Elisabeth princess (written as from 1643) make it possible to see this morals organizing itself gradually, by integrating many elements of morals of Antiquity, but adjusted into Cartesian philosophy so that they express of it also the essential significance. With this occasion, Descartes is brought to compose Passions of the heart, treaty published in the beginning of 1649, in which he seeks to explain “as a physicist” and not as a moralist the various ways in which the body can, by the mechanism independent of his functions, to generate in the heart of passions, i.e. emotions which agitates it and shake it.
Passions are produced by some agitation of the spirits; all are alternatives or combinations of six primitive passions: admiration (astonishment), love and hatred, joy and sadness, desire. The will can oppose their free plan while directing, for example, the attention towards a contrary object with that of passion; consequently, she does not add anything to the movements pineal body, but she changes their direction and, consequently, influences the course of the spirits. This influence is without limits, because our will is infinite, i.e. absolutely free: we have the feeling of it, and, moreover, the existence even of the error proves the free will; doesn't the error consist in making bad use of freedom while adhering to obscure and confused ideas?
Broad outlines of a morals
Descartes did not have time - or perhaps the intention - to develop his morals. He gave us only materials of a morals “final”, similar, essentially, with the morals which it had been formed “by provision” since 1618.
Only the reason can advise us, in any circumstance, which we must do; the farm and constant resolution to carry out it, such is the virtue. While we act thus, certain goods do they escape to us? As inaccessible, and accustom them we regard not to wish them.
This apology for the will translated, at Descartes as at Corneille, the taste of the time for individual energy and a reasonable order. It implies a warning statement against passions; the fight to carry out revêt a double aspect, intellectual - we saw it higher - and medical: by hygiene, by an adapted food, one can moderate the agitation of the animal spirits.
It is not a question, however, of extirpating all passions; some are useful, because they make us feel the true value of the things; they contribute to the softness and the happiness of the life. Let us add that the heart has its own passions, which do not come from the body: such “generosity” or conscience that takes the man of the virtue; such the “intellectual love” which attaches it “to the whole which left”, for example with its country, and more still with God, on which it most entirely depends.
Thus, the man arrives, by processes which point out much more stoical paganism or epicurean that Christianity, with the sovereign bliss, greatest “satisfaction” than it is given to him to reach.
The influence of the Cartesianism
From very good hour, the Cartesianism gains, in spite of persecutions, a brilliant success; it is spread quickly in whole Europe. Such a success would be incomprehensible if one did not see in this new philosophy the expression of a new world, modern world given birth to by the Rebirth. At the time of the first manufactures, Descartes closely envisages the imposing rise of technology and science, dependant between them; informed of the recent scientific discoveries, scientist himself, it formulates the rules of the method and provides to its successors the mathematical instrument essential to their research; it directs physics and biology, the psychophysiology in the way of the mechanism.
Is this to say that nothing remains at his place of the old philosophy? One saw, on the contrary, the oscillations which occur in its thought between science and metaphysics, and which leads to famous “the Cartesian circle”. But Cartesian metaphysics presents original characters: it to the minimum reduces the role of God in creation; it ensures us that we can know a world perfectly from where the phantoms of the scholastic were expelled.
Such as it is, however, it implies a design of the world often different from that which physics involves: between the heart and the body, there is a difference in nature, a rigid opposition; but, on another side, they do not cease acting one on the other; Cogito is the first truth, but on another side, the material world exists independently of our spirit. The contradiction which appears within science itself, between mathematics and physics, pure reasoning and experiment, comes to mingle its effects with those of the conflict which opposes metaphysics and science: if any clear idea is true, we can believe that the heart is immaterial, and that there exists God.
Malebranche, Leibniz and Spinoza will solve - one by the “vision as a God”, the other by the preestablished harmony, the third by its single “substance” - the problems raised by Cartesian dualism, the irreducible parallelism of the “thinking substance” and of the “wide substance”.
Generally, the double current, idealist and materialist, who characterizes modern philosophy, are resulting mainly from Descartes: Leibniz, then Kant and his successors will reduce the world to the thought; Spinoza and, in another way, the Encyclopedists will carry the spirit of free examination until in the fields of the policy and the religion, and will try to explain the world by the world.