History of Modern Philosophy Part 3

Things which we desire are termed good, and those which we shun, evil. Nothing is good per se or absolutely, but only relatively, for a given person, place, time, or set of circ.u.mstances. Different things are good to different men, and there is no objective, universal rule of good and evil, so long as men are considered as individuals, apart from society. A definite criterion of the good is first reached in the state: that is right which the law permits, that wrong which it forbids; good means that which is conducive to the general welfare. In the state of nature nothing is forbidden; nature gives every man a right to everything, and right is coextensive with might. What, then, induces man to abandon the state of nature and enter the state of citizenship? The opinion of Aristotle and Grotius that the state originates in the social impulse is false; for man is essentially not social, but selfish, and nothing but regard for his own interests bids him seek the protection of the state; the civil commonwealth is an artificial product of fear and prudence. The highest good is self-preservation; all other goods, as friendship, riches, wisdom, knowledge, and, above all, power, are valuable only as instruments of the former. The precondition of well-being, for which each man strives by nature, is security for life and health. This is wanting in the state of nature, in which the pa.s.sions govern; for the state of nature is a state of war of everyone against everyone (bellum omnium contra omnes). Each man strives for success and power, and, since he cannot trust his fellow, seeks to subdue, nay, to kill him; each looks upon his fellow as a wolf which he prefers to devour rather than submit himself to the like operation. Now, as no one is so weak as to be incapable of inflicting on his fellows that worst of evils, death, and thus the strongest is unsafe, reason, in the interest of everyone, enjoins a search after peace and the establishment of an ordered community. The conditions of peace are the "laws of nature," which relate both to politics and to morals but which do not attain their full binding authority until they become positive laws, injunctions of the sovereign power. Peace is attainable only when each man, in return for the protection vouchsafed to him, gives up his natural right to all. The compact by which each renounces his natural liberty to do what he pleases, provided all others are ready for the same renunciation,-to which are added, further, the laws of justice (sanct.i.ty of covenants), equity, grat.i.tude, modesty, sociability, mercifulness, etc., whose opposites would bring back the state of nature,-this compact is secured against violation by the transfer of the general power and freedom to a single will (the will of an a.s.sembly or of an individual person), which then represents the general will. The civil contract includes, then, two moments: first, renunciation; second, irrevocable transference and (absolute) submission. The second unites the mult.i.tude into a civil personality, the most perfect unity being vouchsafed by absolute monarchy. The sovereign is the soul of the political body; the officials, its limbs; reward and punishment, its nerves; law and equity, its reason.

The social contract theory has often experienced democratic interpretation and application, both before and since Hobbes's time; and, in fact, it does not include per se the irrevocability of the transfer, the absoluteness of the sovereign power, and the monarchical head, which Hobbes considered indispensable in order to guard against the danger of anarchy. In every abridgment of the supreme power, whether by division or limitation, he sees a step toward the renewal of the state of nature; and he defends with iron rigor the omnipotence of the state and the complete lack of legal status on the part of all individuals in contrast with it. The citizen is not to obey his own conscience, which has simply the value of a private opinion, but the laws, as the public conscience; while the supreme ruler, on the contrary, is superior to the civil laws, for it is he that decrees, interprets, alters, and abrogates them. He is lord over the property, the life, and the death of the citizens, and can do no one wrong. For he alone has retained his original natural right to all, which the rest have entirely and forever renounced. He must have regard, indeed, to the welfare of the people, but he is accountable to G.o.d alone. The obligation of the subject to obey is extinguished in one case only,-when the civil power is incapable of providing him further with external and internal protection. For the rest, Hobbes declares the existing public order the lawful one, the evils of arbitrary rule much more tolerable than the universal hostility of the state of nature, and aversion to tyrants a disease inherited from the republicans of antiquity.

The sovereign, by the laws and by instruction, determines what is good and evil; he determines also what is to be believed. Religion unsanctioned by the state is superst.i.tion. The temporal ruler is also the spiritual ruler, the king, the chief pastor, and the clergy his servants. One and the same community is termed state in so far as it consists of men, and church in so far as it consists of Christian men (the ecclesiastical commonwealth). The dogmas which the law prescribes are to be received without investigation, to be swallowed like pills, without mastication.

The principle that every pa.s.sion and every action is in its nature indifferent, that right and wrong exist only in the state, that the will of a despot is to determine what is moral and what immoral, has given just offense. Moreover, this was not, in fact, Hobbes's deepest conviction. Even without ascribing great importance to isolated statements,[1] it must be admitted that his doctrine was interpreted more narrowly than it was intended. He does not say that no moral distinctions whatever exist before the foundation of the state, but only that the state first supplies a fixed criterion of the good. Moral ideas have a certain currency before this, but they lack power to enforce themselves. Further, when he ascribes the origin of the state to self-interest, this does not mean that reason, conscience, generosity, and love for our fellows are entirely wanting in the state of nature, but only that they are not general enough, and, as against the pa.s.sions, not strong enough to furnish a foundation for the edifice of the state. Not only exaggeration in statement but also uncouthness of thought may be forgiven the representative of a movement which is at once new and strengthened by the consciousness of agreement with a naturalistic theory of knowledge and physics; and the vigor of execution compels admiration, even though many obscurities remain to be deplored (e. g., the relation of the two moral standards, the standard of the reason or natural law and the standard of positive law). And recognition must be accorded to the significant kernel of doctrine formed, on the one hand, by the endeavor to separate ethics from theology, and on the other, by the thoughts-which, it is true, were not perfectly brought out-that the moral is not founded on a natural social impulse, but on a law of the reason, and first gains a definite criterion in society, and that the interests of the individual are inseparably connected with those of the community. In any case, the attempt to form a naturalistic theory of the state would be an undertaking deserving of thanks, even if the promulgation of this theory had done no further service than to challenge refutation.

[Footnote 1: G.o.d inscribed the divine or natural law (Do not that to another, etc.) on the heart of man, when he gave him the reason to rule his actions. The laws of nature are, it is true, not always legally binding (in foro externo), but always and everywhere binding on the conscience (in foro interno). Justice is the virtue which we can measure by civil laws; love, that which we measure by the law of nature merely. The ruler ought to govern in accordance with the law of nature.]

(d) Lord Herbert of Cherbury.-Between Bacon (1605, 1620) and Hobbes (1642, 1651) stands Lord Herbert of Cherbury (1581-1648), who, by his work De Veritate (1624),[1] became the founder of deism, that theory of "natural religion," which, in opposition to the historical dogmatic faith of the Church theology, takes the reason, which is the same in all men, as its basis and morality for its content. Lord Herbert introduces his philosophy of religion by a theory of knowledge which makes universal consent the highest criterion of truth (summa veritatis norma consensus universalis), and bases knowledge on certain self-evident principles (principia), common to all men in virtue of a natural instinct, which gives safe guidance. These common notions (not.i.tiae communes) precede all reflective inquiry, as well as all observation and experience, which would be impossible without them. The most important among them are the religious and ethical maxims of conscience.

[Footnote 1: Tractatus de Veritate prout distinguitur a Revelatione, a Verisimili, a Possibile, et a False. Also, De Religione Gentilium, 1645, complete 1663.]

This natural instinct is both an impulse toward truth and a capacity for good or impulse to self-preservation. The latter extends not only to the individual but to all things with which the individual is connected, to the species, nay, to all the rest of the world, and its final goal is eternal happiness: all natural capacities are directed toward the highest good or toward G.o.d. The sense for the divine may indeed be lulled to sleep or led astray by our free will, but not eradicated. To be rational and to be religious are inseparable; it is religion that distinguishes man from the brute, and no people can be found in which it is lacking. If atheists really exist, they are to be cla.s.sed with the irrational and the insane.

The content of natural religion may be summed up in the following five articles, which all nations confess: 1. That there is a Supreme Being (numen supremum). 2. That he ought to be worshiped. 3. That virtue and piety are the chief elements of worship. 4. That man ought to repent of his sins. 5. That there are rewards and punishments in a future life. Besides these general principles, on the discovery of which Lord Herbert greatly prides himself, the positive religions contain arbitrary additions, which distinguish them from one another and which owe their origin, for the most part, to priestly deception, although the rhapsodies of the poets and the inventions of the philosophers have contributed their share. The essential principles of natural religion (G.o.d, virtue, faith, hope, love, and repentance) come more clearly to light in Christianity than in the religions of heathendom, where they are overgrown with myths and ceremonies.

The Religio Medici (1642) of Sir Thomas Browne shows similar tendencies.

9. Preliminary Survey.

In the line of development from the speculations of Nicolas of Cusa to the establishment of the English philosophy of nature, of religion, and of the state by Bacon, Herbert, and Hobbes, and to the physics of Galileo, modern ideas have manifested themselves with increasing clearness and freedom. Hobbes himself shows thus early the influence of Descartes's decisive step, with which the twilight gives place to the brightness of the morning. In Descartes the empiricism and sensationalism of the English is confronted by rationalism, to which the great thinkers of the Continent continue loyal. In Britain, experience, on the Continent the reason is declared to be the source of cognition; in the former, the point of departure is found in particular impressions of sense, on the latter, in general concepts and principles of the understanding; there the method of observation is inculcated and followed, here, the method of deduction. This ant.i.thesis remained decisive in the development of philosophy down to Kant, so that it has long been customary to distinguish two lines or schools, the Empirical and the Rationalistic, whose parallelism may be exhibited in the following table (when only one date is given it indicates the appearance of the philosopher's chief work):

Empiricism. Rationalism.

Bacon, 1620. (Nicolas, 1450; Bruno, 1584).

Hobbes, 1651. Descartes, died 1650.

Locke, 1690 (1632-1704). Spinoza, (1632-) 1677.

Berkeley, 1710. Leibnitz, 1710.

Hume, 1748. Wolff, died 1754.

We must not forget, indeed, the lively interchange of ideas between the schools (especially the influence of Descartes on Hobbes, and of the latter on Spinoza; further, of Descartes on Locke, and of the latter on Leibnitz) which led to reciprocal approximation and enrichment. Berkeley and Leibnitz, from opposite presuppositions, arrive at the same idealistic conclusion-there is no real world of matter, but only spirits and ideas exist. Hume and Wolff conclude the two lines of development: under the former, empiricism disintegrates into skepticism; under the latter, rationalism stiffens into a scholastic dogmatism, soon to run out into a popular eclecticism of common sense.

If we compare the mental characteristics of the three great nations which, in the period between Descartes and Kant, partic.i.p.ated most productively in the work of philosophy,-the Italians, with their receptive temperament and so active in many fields, exerted a decisive influence on its development and progress in the transition period alone,-it will be seen that the Frenchman tends chiefly to acuteness, the Englishman to clearness and simplicity, the German to profundity of thought. France is the land of mathematical, England of practical, Germany of speculative thinkers; the first is the home of the skeptics, though of the enthusiasts as well; the second, of the realists; the third, of the idealists.

The English philosopher resembles a geographer who, with conscientious care, outlines a map of the region through which he journeys; the Frenchman, an anatomist who, with steady stroke, lays bare the nerves and muscles of the organism; the German, a mountaineer who loses in clear vision of particular objects as much as he gains in loftiness of position and extent of view. The Englishman describes the given reality, the Frenchman a.n.a.lyses it, the German transfigures it.

The English thinker keeps as close as possible to phenomena, and the principles which he uses in the explanation of phenomena themselves lie in the realm of concrete experience. He explains one phenomenon by another; he cla.s.sifies and arranges the given material without a.n.a.lyzing it; he keeps constantly in touch with the popular consciousness. His reverence for reality, as this presents itself to him, and his distrust of far-reaching abstraction, are so strong that it is enough for him to take his bearings from the real, and to give a true reproduction of it, while he willingly renounces the ambition to form it anew in concepts. With this respect for concrete reality he combines a similar reverence for ethical postulates. When the development of a given line of thought threatens to bring him into conflict with practical life, he is honest enough to draw the conclusions which follow from his premises and to give them expression, but he avoids the collision by a simple compromise, shutting up the refinements of philosophy in the study and yielding in practice to the guidance of natural instinct and conscience. His support, therefore, of theories which contradict current views in morals is free from the levity in which the Frenchman indulges. Life and thought are separate fields, contradictions between them are borne in patience, and if science draws its material from life it shows itself grateful for the favor by giving life the benefit of the useful outcome of its labors, and, at the same time, shielding it from the revolutionary or disintegrating effect of its doubtful paradoxes.

While the deliberate craft of English philosophy does not willingly lose sight of the sh.o.r.es of the concrete world, French thought sails boldly and confidently out into the open sea of abstraction. It is not strange that it finds the way to the principles more rapidly than the way back to phenomena. A free road, a fresh start, a straight course-such is the motto of French thinking. Whatever is inconsistent with rectilinearity is ignored, or opposed as unfitting. The line drawn by Descartes through the world between matter and spirit, and that by Rousseau between nature and culture, are distinctive of the philosophical character of their countrymen. Dualism is to them entirely congenial; it satisfies their need for clearness, and with this they are content. Ant.i.thesis is in the Frenchman's blood; he thinks in it and speaks in it, in the salon or on the platform, in witty jest or in scientific earnestness of thought. Either A or not-A, and there is no middle ground. This habit of precision and sharp a.n.a.lysis facilitates the formation of closed parties, whereas each individual German, in philosophy as in politics, forms a party of his own. The demand for the removal of the rubbish of existing systems and the sanguine return to the sources, give French philosophy an unhistorical, radical, and revolutionary character. Minds of the second order, who are incapable of taking by themselves the step from that which is given to the sources, prove their radicalism by following down to the roots that which others have begun (so Condillac and the sensationalism of Locke). Moreover, philosophical principles are to be translated into action; the thinker has shown himself the doctrinaire in his destructive a.n.a.lysis of that which is given, so, also, he hopes to play the dictator by overturning existing inst.i.tutions and establishing a new order of things,-only his courageous endeavor flags as soon in the region of practice as in that of theory.

The German lacks the happy faculty, which distinguishes the two nations just discussed, of isolating a problem near at hand, and he is accustomed to begin his system with Leda's egg; but, by way of compensation, he combines the lofty flight of the French with the phlegmatic endurance of the English, i.e., he seeks his principles far above experience, but, instead of stopping with the establishment of points of view or when he has set the note, he carries his principles through in detail with loving industry and comprehensive architectonic skill. While common sense turns the scale with the English and a.n.a.lytical thought with the French, the German allows the fancy and the heart to take an important part in the discussion, though in such a way that the several faculties work together and in harmony. While in France rationalism, mysticism, and the philosophy of the heart were divided among different thinkers (Descartes, Malebranche and Pascal, Rousseau), there is in every German philosopher something of all three. The skeptical Kant provides a refuge for the postulates of thought in the sanctuary of faith; the earnest, energetic Fichte, toward the end of his life, takes his place among the mystics; Sch.e.l.ling thinks with the fancy and dreams with the understanding; and under the broad cloak of the Hegelian dialectic method, beside the reflection of the Critique of Reason and of the Science of Knowledge, the fancies of the Philosophy of Nature, the deep inwardness of Bohme, even the whole wealth of empirical fact, found a place. As synthesis is predominant in his view of things, so a harmonizing, conciliatory tendency a.s.serts itself in his relations to his predecessors: the results of previous philosophers are neither discarded out of hand nor accepted in the ma.s.s, but all that appears in any way useful or akin to the new system is wrought in at its proper place, though often with considerable transformation. In this work of mediation there is considerable loss in definiteness, the just and comprehensive consideration of the most diverse interests not always making good the loss. And since such a philosophy, as we have already shown, engages the whole man, its disciple has neither impulse nor strength left for reforming labors; while, on the other hand, he perceives no external call to undertake them, since he views the world through the gla.s.ses of his system. Thus philosophy in Germany, pursued chiefly by specialists, remains a professional affair, and has not exercised a direct transforming influence on life (for Fichte, who helped to philosophize the French out of Germany, was an exception); but its influence has been the greater in the special sciences, which in Germany more than any other land are handled in a philosophic spirit.

The mental characteristics of these nations are reflected also in their methods of presentation. The style of the English philosopher is sober, comprehensible, diffuse, and slightly wearisome. The French use a fluent, elegant, lucid style which entertains and dazzles by its epigrammatic phrases, in which not infrequently the epigram rules the thought. The German expresses his solid, thoughtful positions in a form which is at once ponderous and not easily understood; each writer constructs his own terminology, with a liberal admixture of foreign expressions, and the length of his paragraphs is exceeded only by the thickness of his books. These national distinctions may be traced even in externals. The Englishman makes his divisions as they present themselves at first thought, and rather from a practical than from a logical point of view. The a.n.a.lytic Frenchman prefers dichotomy, while trichotomy corresponds to the synthetic, systematic character of German thinking; and Kant's nave delight, because in each cla.s.s the third category unites its two predecessors, has been often experienced by many of his countrymen at the sight of their own trichotomies.

The division of labor in the pre-Kantian philosophy among these three nationalities entirely agrees with the account given of the peculiarities of their philosophical endowment. The beginning falls to the share of France; Locke receives that tangled skein, the problem of knowledge, from the hand of Descartes, and pa.s.ses it on to Leibnitz; and while the Illumination in all three countries is converting the gold inherited from Locke and Leibnitz into small coin, the solution of the riddle rings out from Konigsberg.

PART I.

FROM DESCARTES TO KANT.

CHAPTER II.

DESCARTES.

The long conflict with Scholasticism, which had been carried on with ever increasing energy and ever sharper weapons, was brought by Descartes to a victorious close. The new movement, long desired, long sought, and prepared for from many directions, at length appears, ready and well-established. Descartes accomplishes everything needful with the sure simplicity of genius. He furnishes philosophy with a settled point of departure in self-consciousness, offers her a method sure to succeed in deduction from clear and distinct conceptions, and a.s.signs her the mechanical explanation of nature as her most imperative and fruitful mission.

Rene Descartes was born at La Haye in Touraine, in 1596, and died at Stockholm in 1650. Of the studies taught in the Jesuit school at La Fleche, mathematics alone was able to satisfy his craving for clear and certain knowledge. The years 1613-17 he spent in Paris; then he enlisted in the military service of the Netherlands, and, in 1619, in that of Bavaria. While in winter quarters at Neuburg, he vowed a pilgrimage to Loretto if the Virgin would show him a way of escape from his tormenting doubts; and made the saving discovery of the "foundations of a wonderful science." At the end of four years this vow was fulfilled. On his return to Paris (1625), he was besought by his learned friends to give to the world his epoch-making ideas. Though, to escape the distractions of society, he kept his residence secret, as he had done during his first stay in Paris, and frequently changed it, he was still unable to secure the complete privacy and leisure for scientific work which he desired. Therefore he went to Holland in 1629, and spent twenty years of quiet productivity in Amsterdam, Franecker, Utrecht, Leeuwarden, Egmond, Harderwijk, Leyden, the palace of Endegeest, and five other places. His work here was interrupted only by a few journeys, but much disturbed in its later years by annoying controversies with the theologian Gisbert Voetius of Utrecht, with Regius, a pupil who had deserted him, and with professors from Leyden. His correspondence with his French friends was conducted through Pere Mersenne. In 1649 he yielded to pressing invitations from Queen Christina of Sweden and removed to Stockholm. There his weak const.i.tution was not adequate to the severity of the climate, and death overtook him within a few months.

The two decades of retirement in the Netherlands were Descartes's productive period. His motive in developing and writing out his thoughts was, essentially, the desire not to disappoint the widely spread belief that he was in possession of a philosophy more certain than the common one. The work ent.i.tled Le Monde, begun in 1630 and almost completed, remained unprinted, as the condemnation of Galileo (1632) frightened our philosopher from publication; fragments of it only, and a brief summary, appeared after the author's death. The chief works, the Discourse on Method, the Meditations on the First Philosophy, and the Principles of Philosophy appeared between 1637 and 1644,-the Discours de la Methode in 1637, together with three dissertations (the "Dioptrics," the "Meteors," and the "Geometry"), under the common t.i.tle, Essais Philosophiques. To the (six) Meditationes de Prima Philosophia, published in 1641, and dedicated to the Paris Sorbonne, are appended the objections of various savants to whom the work had been communicated in ma.n.u.script, together with Descartes's rejoinders. He himself considered the criticisms of Arnauld, printed fourth in order, as the most important. The Third Objections are from Hobbes, the Fifth from Ga.s.sendi, the First, which were also the first received, from the theologian Caterus of Antwerp, while the Second and Sixth, collected by Mersenne, are from various theologians and mathematicians. In the second edition there were added, further, the Seventh Objections, by the Jesuit Bourdin, and the Replies of the author thereto. The four books of the Principia Philosophiae, published in 1644 and dedicated to Elizabeth, Countess Palatine, give a systematic presentation of the new philosophy. The Discourse on Method appeared, 1644, in a Latin translation, the Meditations and the Principles in French, in 1647. The Treatise on the Pa.s.sions was published in 1650; the Letters, 1657-67, in French, 1668, in Latin. The Opera Postuma, 1701, beside the Compendium of Music (written in 1618) and other portions of his posthumous writings, contain the "Rules for the Direction of the Mind," supposed to have been written in 1629, and the "Search for Truth by the Light of Nature." The complete works have been often published, both in Latin and in French. The eleven volume edition of Cousin appeared in 1824-26.[1]

[Footnote 1: Of the many treatises on the philosophy of Descartes those of C. Schaarschmidt (Descartes und Spinoza, 1850) and J.H. Lowe, 1855, may be mentioned. Further, M. Heinze has discussed Die Sittenlehre des Descartes, 1872; Ed. Grimm, Descartes' Lehre von den angeborenen Ideen, 1873; G. Glogau, Darlegung und Kritik des Grundgedankens der Cartesianisch. Metaphysik (Zeitschrift fur Philosophie, vol. lxxiii. p. 209 seq.), 1878; Paul Natorp, Descartes' Erkenntnisstheorie, 1882; and Kas. Twardowski, Idee und Perception in Descartes, 1892. In French, Francisque Bouillier (Histoire de la Philosophie Cartesienne, 1854) and E. Saisset (Precurseurs et Disciples de Descartes, 1862) have written on Cartesianism. [The Method, Meditations, and Selections from the Principles have been translated into English by John Veitch, 5th ed., 1879, and others since; and H.A.P. Torrey has published The Philosophy of Descartes in Extracts from his Writings, 1892 (Sneath's Modern Philosophers). The English reader may be referred, also, to Mahaffy's Descartes, 1880, in Blackwood's Philosophical Cla.s.sics; to the article "Cartesianism," Encyclopedia Britannica, 9th ed., vol. v., by Edward Caird; and, for a complete discussion, to the English translation of Fischer's Descartes and his School' by J.P. Gordy, 1887.-TR.]]

We begin our discussion with Descartes's noetical and metaphysical principles, and then take up in order his doctrine of nature and of man.

1. The Principles.

That which pa.s.ses nowadays for science, and is taught as such in the schools, is nothing but a ma.s.s of disconnected, uncertain, and often contradictory opinions. A principle of unity and certainty is entirely lacking. If anything permanent and irrefutable is to be accomplished in science, everything hitherto considered true must be thoroughly demolished and built up anew. For we come into the world as children and we form judgments of things, or repeat them after others, before we have come into the full possession of our intellectual powers; so that it is no wonder that we are filled with a mult.i.tude of prejudices, from which we can thoroughly escape only by considering everything doubtful which shows the least sign of uncertainty. Let us renounce, therefore, all our old views, in order later to accept better ones in their stead; or, perchance, to take the former up again after they shall have stood the test of rational criticism. The recognized precaution, never to put complete confidence in that which has once deceived us, holds of our relation to the senses as elsewhere. It is certain that they sometimes deceive us-perhaps they do so always. Again, we dream every day of things which nowhere exist, and there is no certain criterion by which to distinguish our dreams from our waking moments,-what guarantee have we, then, that we are not always dreaming? Therefore, our doubt must first of all be directed to the existence of sense-objects. Nay, even mathematics must be suspected in spite of the apparent certainty of its axioms and demonstrations, since controversy and error are found in it also.

I doubt or deny, then, that the world is what it appears to be, that there is a G.o.d, that external objects exist, that I have a body, that twice two are four. One thing, however, it is impossible for me to bring into question, namely, that I myself, who exercise this doubting function, exist. There is one single point at which doubt is forced to halt-at the doubter, at the self-existence of the thinker. I can doubt everything except that I doubt, and that, in doubting, I am. Even if a superior being sought to deceive me in all my thinking, he could not succeed unless I existed, he could not cause me not to exist so long as I thought. To be deceived means to think falsely; but that something is thought, no matter what it be, is no deception. It might be true, indeed, that nothing at all existed; but then there would be no one to conceive this non-existence. Granted that everything may be a mistake; yet the being mistaken, the thinking is not a mistake. Everything is denied, but the denier remains. The whole content of consciousness is destroyed; consciousness itself, the doubting activity, the being of the thinker, is indestructible. Cogitatio sola a me divelli nequit. Thus the settled point of departure required for knowledge is found in the self-cert.i.tude of the thinking ego. From the fact that I doubt, i.e., think, it follows that I, the doubter, the thinker, am. Cogito, ergo sum is the first and most certain of all truths.

The principle, "I think, therefore I am," is not to be considered a deduction from the major premise, "Whatever thinks exists." It is rather true that this general proposition is derived from the particular and earlier one. I must first realize in my own experience that, as thinking, I exist, before I can reach the general conclusion that thought and existence are inseparable. This fundamental truth is thus not a syllogism, but a not further deducible, self-evident, immediate cognition, a pure intuition-sum cogitans. Now, if my existence is revealed by my activity of thought, if my thought is my being, and the converse, if in me thought and existence are identical, then I am a being whose essence consists in thinking. I am a spirit, an ego, a rational soul. My existence follows only from my thinking, not from any chance action. Ambulo ergo sum would not be valid, but mihi videor or puto me ambulare, ergo sum. If I believe I am walking, I may undoubtedly be deceived concerning the outward action (as, for instance, in dreams), but never concerning my inward belief. Cogitatio includes all the conscious activities of the mind, volition, emotion, and sensation, as well as representation and cognition; they are all modi cogitandi. The existence of the mind is therefore the most certain of all things. We know the soul better than the body. It is for the present the only certainty, and every other is dependent on this, the highest of all.

What, then, is the peculiarity of this first and most certain knowledge which renders it self-evident and independent of all proof, which makes us absolutely unable to doubt it? Its entire clearness and distinctness. Accordingly, I may conclude that everything which I perceive as clearly and distinctly as the cogito ergo sum is also true, and I reach this general rule, omne est verum, quod clare et distincte percipio. So far, then, we have gained three things: a challenge; to be inscribed over the portals of certified knowledge, de omnibus dubitandum; a basal truth, sum cogitans; a criterion of truth, clara et distinct a perceptio.

The doubt of Descartes is not the expression of a resigned spirit which renounces the unattainable; it is precept, not doctrine, the starting point of philosophy, not its conclusion, a methodological instrument in the hand of a strong and confident longing for truth, which makes use of doubt to find the indubitable. It is not aimed at the possibility of attaining knowledge, but at the opinion that it has already been attained, at the credulity of the age, at its excessive tendency toward historical and poly-historical study, which confuses the acquisition and handing down of information with knowledge of the truth. That knowledge alone is certain which is self-attained and self-tested-and this cannot be learned or handed down; it can only be rediscovered through examination and experience. Instead of taking one's own unsupported conjectures or the opinions of others as a guide, the secret of the search for truth is to become independent and of age, to think for one's self; and the only remedy against the dangers of self-deception and the ease of repet.i.tion is to be found in doubting everything hitherto considered true. This is the meaning of the Cartesian doubt, which is more comprehensive and more thorough than the Baconian. Descartes disputed only the cert.i.tude of the knowledge previously attained, not the possibility of knowledge-for of the latter no man is more firmly convinced than he. He is a rationalist, not a skeptic. The intellect is a.s.sured against error just as soon as, freed from hindrances, it remains true to itself, as it puts forth all its powers and lets nothing pa.s.s for truth which is not clearly and distinctly known. Descartes demands the same thing for the human understanding as Rousseau at a later period for the heart: a return to uncorrupted nature. This faith in the unartificial, the original, the natural, this radical and naturalistic tendency is characteristically French. The purification of the mind, its deliverance from the rubbish of scholastic learning, from the pressure of authority, and from inert acceptance of the thinking of others-this is all. Descartes finds the clearest proof of the mind's capacity for truth in mathematics, whose trustworthiness he never seriously questioned, but only hypothetically, in order to exhibit the still higher certainty of the "I think, therefore I am." He wants to give philosophy the stable character which had so impressed him in mathematics when he was a boy, and recommends her, therefore, not merely the evidence of mathematics as a general example, but the mathematical method for definite imitation. Metaphysics, like mathematics, must derive its conclusions by deduction from self-evident principles. Thus the geometrical method begins its rule in philosophy, a rule not always attended with beneficial results.

With this criterion of truth Descartes advances to the consideration of ideas. He distinguishes volition and judgment from ideas in the narrow sense (imagines), and divides the latter, according to their origin, into three cla.s.ses: ideae innatae, advent.i.tiae, a me ipso factae, considering the second cla.s.s, the "advent.i.tious" ideas, the most numerous, but the first, the "innate" ideas, the most important. No idea is higher or clearer than the idea of G.o.d or the most perfect being. Whence comes this idea? That every idea must have a cause, follows from the "clear and distinct" principle that nothing produces nothing. It follows from this same principle, ex nihilo nihil fit, however, that the cause must contain as much reality or perfection-realitas and perfectio are synonymous-as the effect, for otherwise the overplus would have come from nothing. So much ("objective," representative) reality contained in an idea, so much or more ("formal," actual) reality must be contained in its cause. The idea of G.o.d as infinite, independent, omnipotent, omniscient, and creative substance, has not come to me through the senses, nor have I formed it myself. The power to conceive a being more perfect than myself, can have only come from someone who is more perfect in reality than I. Since I know that the infinite contains more reality than the finite, I may conclude that the idea of the infinite has not been derived from the idea of the finite by abstraction and negation; it precedes the latter, and I become conscious of my defects and my finitude only by comparison with the absolute perfection of G.o.d. This idea, then, must have been implanted in me by G.o.d himself. The idea of G.o.d is an original endowment; it is as innate as the idea of myself. However incomplete it may be, it is still sufficient to give a knowledge of G.o.d's existence, although not a perfect comprehension of his being, just as a man may skirt a mountain without encircling it.

Descartes brings in the idea of G.o.d in order to escape solipsism. So long as the self-consciousness of the ego remained the only certainty, there was no conclusive basis for the a.s.sumption that anything exists beyond self, that the ideas which apparently come from without are really occasioned by external things and do not spring from the mind itself. For our natural instinct to refer them to objects without us might well be deceptive. It is only through the idea of G.o.d, and by help of the principle that the cause must contain at least as much reality as the effect, that I am taken beyond myself and a.s.sured that I am not the only thing in the world. For as this idea contains more of representative, than I of actual reality, I cannot have been its cause.

To this empirical argument, which derives G.o.d's existence from our idea of G.o.d (from the fact that we have an idea of him), Descartes joins the (modified) ontological argument of Anselm, which deduces the existence of G.o.d from the concept of G.o.d. While the ideas of all other things include only the possibility of existence, necessary existence is inseparable from the concept of the most perfect being. G.o.d cannot be thought apart from existence; he has the ground of his existence in himself; he is a se or causa sui. Finally, Descartes adds a third argument. The idea of perfections which I do not possess can only have been imparted to me by a more perfect being than I, which has bestowed on me all that I am and all that I am capable of becoming. If I had created myself, I would have bestowed upon myself these absent perfections also. And the existence of a plurality of causes is negatived by the supreme perfection which I conceive in the idea of G.o.d, the indivisible unity of his attributes. Among the attributes of G.o.d his veracity is of special importance. It is impossible that he should will to deceive us; that he should be the cause of our errors. G.o.d would be a deceiver, if he had endowed us with a reason to which error should appear true, even when it uses all its foresight in avoiding it and a.s.sents only to that which it clearly and distinctly perceives. Error is man's own fault; he falls into it only when he misuses the divine gift of knowledge, which includes its own standard. Thus Descartes finds new confirmation for his test of truth in the veracitas dei. Erdmann has given a better defense of Descartes than the philosopher himself against the charge that this is arguing in a circle, inasmuch as the existence of G.o.d is proved by the criterion of truth, and then the latter by the former: The criterion of cert.i.tude is the ratio cognoscendi of G.o.d's existence; G.o.d is the ratio essendi of the criterion of cert.i.tude. In the order of existence G.o.d is first, he creates the reason together with its criterion; in the order of knowledge the criterion precedes, and G.o.d's existence follows from it. Descartes himself endeavors to avoid the circle by making intuitive knowledge self-evident, and by not bringing in the appeal to G.o.d's veracity in demonstrative knowledge until, in reflective thought, we no longer have each separate link in the chain of proof present to our minds with full intuitive certainty, but only remember that we have previously understood the matter with clearness and distinctness.

Our ideas represent in part things, in part qualities. Substance is defined by the concept of independence as res quae ita exist.i.t, ut nulla alia re indigeat ad existendum; a pregnant definition with which the concept of substance gains the leadership in metaphysics, which it held till the time of Hume and Kant, sharing it then with the conception of cause or, rather, relinquishing it to the latter. The Spinozistic conclusion that, according to the strict meaning of this definition, there is but one substance, G.o.d, who, as causa sui, has absolutely no need of any other thing in order to his existence, was announced by Descartes himself. If created substances are under discussion, the term does not apply to them in the same sense (not univoce) as when we speak of the infinite substance; created beings require a different explanation, they are things which need for their existence only the co-operation of G.o.d, and have no need of one another. Substance is cognized through its qualities, among which one is pre-eminent from the fact that it expresses the essence or nature of the thing, and that it is conceived through itself, without the aid of the others, while they presuppose it and cannot be thought without it. The former fundamental properties are termed attributes, and these secondary ones, modes or accidents. Position, figure, motion, are contingent properties of body; they presuppose that it is extended or spatial; they are modi extensionis, as feeling, volition, desire, representation, and judgment are possible only in a conscious being, and hence are merely modifications of thought. Extension is the essential or const.i.tutive attribute of body, and thought of mind. Body is never without extension, and mind never without thought-mens semper cogitat. Guided by the self-evident principle that the non-existent has no properties, we argue from a perceived quality to a substance as its possessor or support. Substances are distinct from one another when we can clearly and distinctly cognize one without the other. Now, we can adequately conceive mind without a corporeal attribute and body without a spiritual one; the former has nothing of extension in it, the latter nothing of thought: hence thinking substance and extended substance are entirely distinct and have nothing in common. Matter and mind are distinct realiter, matter and extension idealiter merely. Thus we attain three clear and distinct ideas, three eternal verities: substantia infinita sive deus, substantia finita cogitans sive mens, substantia extensa sive corpus.

By this abrupt contraposition of body and mind as reciprocally independent substances, Descartes founded that dualism, as whose typical representative he is still honored or opposed. This dualism between the material and spiritual worlds belongs to those standpoints which are valid without being ultimate truth; on the pyramid of metaphysical knowledge it takes a high, but not the highest, place. We may not rest in it, yet it retains a permanent value in opposition to subordinate theories. It is in the right against a materialism which still lacks insight into the essential distinction between mind and matter, thought and extension, consciousness and motion; it loses its validity when, with a full consideration and conservation of the distinction between these two spheres, we succeed in bridging over the gulf between them, whether this is accomplished through a philosophy of ident.i.ty, like that of Spinoza and Sch.e.l.ling, or by an idealism, like that of Leibnitz or Fichte. In any case philosophy retains as an inalienable possession the negative conclusion, that, in view of the heterogeneity of consciousness and motion, the inner life is not reducible to material phenomena. This clear and simple distinction, which sets bounds to every confusion of spiritual and material existence, was an act of emanc.i.p.ation; it worked on the sultry intellectual atmosphere of the time with the purifying and illuminating power of a lightning flash. We shall find the later development of philosophy starting from the Cartesian dualism.

Descartes himself looked upon the fundamental principles which have now been discussed as merely the foundation for his life work, as the entrance portal to his cosmology. Posterity has judged otherwise; it finds his chief work in that which he considered a mere preparation for it. The start from doubt, the self-cert.i.tude of the thinking ego, the rational criterion of cert.i.tude, the question of the origin of ideas, the concept of substance, the essential distinction between conscious activity and corporeal being, and, also, the principle of thoroughgoing mechanism in the material world (from his philosophy of nature)-these are the thoughts which a.s.sure his immortality. The vestibule has brought the builder more fame, and has proved more enduring, than the temple: of the latter only the ruins remain; the former has remained undestroyed through the centuries.

2. Nature.

What guarantee have we for the existence of material objects affecting our senses? That the ideas of sense do not come from ourselves, is shown by the fact that it is not in our power to determine the objects which we perceive, or the character of our perception of them. The supposition that G.o.d has caused our perceptions directly, or by means of something which has no resemblance whatever to an external object extended in three dimensions and movable, is excluded by the fact that G.o.d is not a deceiver. In reliance on G.o.d's veracity we may accept as true whatever the reason declares concerning body, though not all the reports of the senses, which so often deceive us. At the instance of the senses we clearly and distinctly perceive matter distinct from our mind and from G.o.d, extended in three dimensions, length, breadth, and depth, with variously formed and variously moving parts, which occasion in us sensations of many kinds. The belief that perception makes known things as they really are is a prejudice of sense to be discarded; on the contrary, it merely informs us concerning the utility or harmfulness of objects, concerning their relation to man as a being composed of soul and body. (The body is that material thing which is very intimately joined with the mind, and occasions in the latter certain feelings, e.g., pain, which as merely cogitative it would not have.) Sense qualities, as color, sound, odor, cannot const.i.tute the essence of matter, for their variation or loss changes nothing in it; I can abstract from them without the material thing disappearing.[1] There is one property, however, extensive magnitude (quant.i.tas), whose removal would imply the destruction of matter itself. Thus I perceive by pure thought that the essence of matter consists in extension, in that which const.i.tutes the object of geometry, in that magnitude which is divisible, figurable, and movable. This thesis (corpus = extensio sive spatium) is next defended by Descartes against several objections. In reply to the objection drawn from the condensation and rarefaction of bodies, he urges that the apparent increase or decrease in extension is, in fact, a mere change of figure; that the rarefaction of a body depends on the increase in size of the intervals between its parts, and the entrance into them of foreign bodies, just as a sponge swells up when its pores become filled with water and, therefore, enlarged. The demand that the pores, and the bodies which force their way into them, should always be perceptible to the senses, is groundless. He meets the second point, that we call extension by itself s.p.a.ce, and not body, by maintaining that the distinction between extension and corporeal substance is a distinction in thought, and not in reality; that attribute and substance, mathematical and physical bodies, are not distinct in fact but only in our thought of them. We apply the term s.p.a.ce to extension in general, as an abstraction, and body to a given individual, determinate, limited extension. In reality, wherever extension is, there substance is also,-the non-existent has no extension,-and wherever s.p.a.ce is, there matter is also. Empty s.p.a.ce does not exist. When we say a vessel is empty, we mean that the bodies which fill it are imperceptible; if it were absolutely empty its sides would touch. Descartes argues against the atomic theory and against the finitude of the world, as he argues against empty s.p.a.ce: matter, as well as s.p.a.ce, has no smallest, indivisible parts, and the extension of the world has no end. In the identification of s.p.a.ce and matter the former receives fullness from the latter, and the latter unlimitedness from the former, both internal unlimitedness (endless divisibility) and external (boundlessness). Hence there are not several matters but only one (h.o.m.ogeneous) matter, and only one (illimitable) world.

[Footnote 1: They are merely subjective states in the perceiver, and entirely unlike the motions which give rise to them, although there is a certain agreement, as the differences and variations in sensation are paralleled by those in the object.]

Matter is divisible, figurable, movable quant.i.ty. Natural science needs no other principles than these indisputably true conceptions, by which all natural phenomena may be explained, and must employ no others. The most important is motion, on which all the diversity of forms depends. Corporeal being has been shown to be extension; corporeal becoming is motion. Motion is defined as "the transporting of one part of matter, or of one body, from the vicinity of those bodies that are in immediate contact with it, or which we regard as at rest, to the vicinity of other bodies." This separation of bodies is reciprocal, hence it is a matter of choice which shall be considered at rest. Besides its own proper motion in reference to the bodies in its immediate vicinity, a body can partic.i.p.ate in very many other motions: the traveler walking back and forth on the deck of a ship, for instance, in the motion of the vessel, of the waves, and of the earth. The common view of motion as an activity is erroneous; since it requires force not only to set in motion bodies which are at rest, but also to stop those which are in motion, it is clear that motion implies no more activity than rest. Both are simply different states of matter. Since there is no empty s.p.a.ce, each motion spreads to a whole circle of bodies: A forces B out of its place, B drives out C, and so on, until Z takes up the position which A has left.

The ultimate cause of motion is G.o.d. He has created bodies with an original measure of motion and rest, and, in accordance with his immutable character, he preserves this quant.i.ty of motion unchanged: it remains constant in the world as a whole, though it varies in individual bodies. For with the power to create or destroy motion bodies lack, further, the power to alter their quant.i.ty of motion. By the side of G.o.d, the primary cause of motion, the laws of motion appear as secondary causes. The first of these is the one become familiar under the name, law of inertia: Everything continues of itself in the state (of motion or rest) in which it is, and changes its state only as a result of some extraneous cause. The second of these laws, which are so valuable in mechanics, runs: Every portion of matter tends to continue a motion which has been begun in the same direction, hence in a straight line, and changes its direction only under the influence of another body, as in the case of the circle above described. Descartes bases these laws on the unchangeableness of G.o.d and the simplicity of his world-conserving (i.e., constantly creative) activity. The third law relates to the communication of motion; but Descartes does not recognize the equality of action and reaction as universally as the fact demands. If a body in motion meets another body, and its power (to continue its motion in a straight line) is less than the resistance of the other on which it has impinged, it retains its motion, but in a different direction: it rebounds in the opposite direction. If, on the contrary, its force is greater, it carries the other body along with it, and loses so much of its own motion as it imparts to the latter. The seven further rules added to these contain much that is erroneous. As actio in distans is rejected, all the phenomena of motion are traced back to pressure and impulse. The distinction between fluid and solid bodies is based on the greater or less mobility of their parts.

The leading principle in the special part of the Cartesian physics,-we can only briefly sketch it,-which embraces, first, celestial, and, then, terrestial phenomena, is the axiom that we cannot estimate G.o.d's power and goodness too highly, nor ourselves too meanly. It is presumptuous to seek to comprehend the purposes of G.o.d in creation, to consider ourselves partic.i.p.ants in his plans, to imagine that things exist simply for our sake-there are many things which no man sees and which are of advantage to none. Nothing is to be interpreted teleologically, but all must be interpreted from clearly known attributes, hence purely mechanically. After treating of the distances of the various heavenly bodies, of the independent light of the sun and the fixed stars and the reflected light of the planets, among which the earth belongs, Descartes discusses the motion of the heavenly bodies. In reference to the motion of the earth he seeks a middle course between the theories of Copernicus and Tycho Brahe. He agrees with Copernicus in the main point, but, in reliance on his definition of motion, maintains that the earth is at rest, viz., in respect to its immediate surroundings. It is clear that the harmony of his views with those of the Church (though it was only a verbal agreement) was not unwelcome to him. According to his hypothesis,-as he suggests, perhaps an erroneous hypothesis,-the fluid matter which fills the heavenly s.p.a.ces, and which may be compared to a vortex or whirlpool, circles about the sun and carries the planets along with it. Thus the planets move in relation to the sun, but are at rest in relation to the adjacent portions of the matter of the heavens. In view of the biblical doctrine, according to which the world and all that therein is was created at a stroke, he apologetically describes his attempt to explain the origin of the world from chaos under the laws of motion as a scientific fiction, intended merely to make the process more comprehensible. It is more easily conceivable, if we think of the things in the world as though they had been gradually formed from elements, as the plant develops from the seed. We now pa.s.s to the Cartesian anthropology, with its three chief objects: the body, the soul, and the union of the two.