French proud of their countryman, and resolve to consign his remains to their national cemetery in Paris in 1666.

In reviewing his life, we find neither his virtues conspicuous, nor his defects glaring. The hero of a philosophical revolution, he despised the instructions of the past, and had unbounded confidence in his own opinions. He was fond of money, and ambitious of fame. He was tenacious of his own discoveries; yet he was generally thought to be a literary pilferer from other men's treasures. His mind was subtle, ingenious, and profound. He saw, with intuitive rapidity, the most recondite principles, and disengaged other men's fallacies with marvellous precision and logical tact. His discoveries were numerous, not because he made successful generalizations of facts, but the most happy of guesses, and the most sagacious deductions from them.

He wrote for the people as well as for the philosophers of his age, and thus made public opinion his ultimate appeal. He wrote in a language that is European, and in a style not far from perfection. While Dugald Stewart has hailed him as father of mental philosophy, Voltaire and V. Cousin hail him as the founder of French literature.

The influence of the Cartesian philosophy is boundless; its ramifications innumerable. We will endeavour to characterise certain parts of it, and, as far as our limited space allows, describe their results. It would be unjust to the memory of Descartes to overlook the flood of light he poured over mathematical science by the discovery which he thus describes in his 'Discourse on Method:'

I had no intention of attempting to master all the particular sciences commonly denominated mathematics; but observing that, however different their objects, they all agree in considering only the various relations or proportions subsisting among those objects, I thought it best to consider these proportions in the most general form possible. . . . Perceiving, further, that in order to understand these relations, I should have to consider them one by one, and sometimes only to bear them in mind, or embrace them in the aggregate, I thought that in order the better to consider them individually, I should view them as subsisting between straight lines, . . . and express them by certain characters the briefest possible. In this way, I believed that I could borrow all that was best both in geometrical analysis and in algebra, and correct all the defects of the one by the help of the other.'-Discourse on Method, &c., translated from the French, pp. 62, 63.

The application of algebra to geometry has done for the

Hallam, in his Literature of Europe,' has given abundant material from which to form an opinion on the charge of plagiarism brought by Leibnitz and others against Descartes : vols. ii. and iii.

mathematical sciences what the application of the expansive power of steam to the creation of a motive force has done for the mechanical arts. As far as astronomers and mathematicians are indebted to this great principle for the magnificent results of their study, during the last two hundred years, they owe them also to the fertile and creative mind of Descartes. But we must not identify his labours in astronomical science with the farreaching and almost miraculous results of Newton's genius and toil,

'Voyaging through strange seas of thought alone,'

as Wordsworth has it. And here we differ from M. Bouillier, who, speaking of the hypotheses of Descartes and of Newton,

says:

'La difference entre les deux hypothèses est peut-être moins grande que d'ordinaire, on se l'imagine. Toutes deux envisagent l'univers sous un même point de vue. Pour Newton comme pour Descartes le problème de la constitution de l'univers est un problème de mécanique... C'est, donc, Descartes qui, le premier a eu l'idée que tous les mondes étaient également assujétis aux lois générales de la mécanique. ... Par cette seule idée il a préparé Newton; il a fait peut-être plus que Newton.'-Histoire et Critique de la Révolution Cartésienne, p. 432.

The prize-essayist of the French Academy seems to have forgotten the progress that had been made in the direction of Newton's great discovery by Copernicus, Tycho Brahe, Kepler, Galileo, Hooke, and others. Descartes sought an hypothesis which might explain the origin and continuance of the movements of the solar system, and at the same time solve the mystery of light, and proclaim the prima materia of the universe. Newton, and others, perceived that the great problem was, in the first instance, the discovery of the central force which, when acting on the dynamical relations of two and three related bodies, would satisfy the conditions imposed by the observations of Kepler. Descartes only suggested what was analogous to the supposition of central forces, in his Théorie des Tourbillons ;' but Newton, having considered as settled the fact that central forces would deflect into a curve resembling an ellipse the bodies that were moving laterally to the centre of force, proved that the central force, required to account for alleged and observed facts, was in the direct ratio of the masses in question, and in the inverse duplicate ratio of their distances from the centre. Descartes endeavoured to show à priori how the world must have been created; Newton, to interpret the law of its conservation. And, in manifest contradiction to the statements of Bouillier, Descartes either would not appreciate, or did not comprehend, the merit of Galileo, who was at once a disciple of Bacon, his

own contemporary, and the true philosophical precursor of Newton. We allude to the mathematical genius of Descartes, which was unquestionable, and fruitful of many valuable results, because it forms a key to the method which he pursued in his metaphysical investigations. Benedict Spinoza fully developed the hints which Descartes threw out in his replies to the objections of Mersenne, and presented his metaphysics in a geometrical form; but the intense desire to start from first principles, and to carry the force and vitality of their accuracy into the extreme ramifications of his reasonings on metaphysical subjects, permeates the entire philosophy of Descartes; and from his mathematical success, we may explain his eagerness to start from some absolute and irreversible certainty in his solution of the great ontological problem. Sometimes we are assured, in criticisms on Descartes, that the celebrated criterion- Whatsoever is clearly and distinctly perceived by us is true in itself,' is the basis of all his reasonings; and, sometimes, that his famous cogito ergo sum' is the basis of this criterion. This confusion may occur from the different degree of prominence given by our author to these points of departure, in the three great works to which we have referred-the Discourse on Method,' the 'Meditations,' and the 'Principia.' In the last-mentioned work, he is laying the foundation of all his subsequent raticionations, and there we find consciousness made the prominent standard of appeal. In the Discourse on Method,' he is describing the process by which we may arrive at truth, and the criterion' receives the principal attention. It is trifling with Descartes to quibble, with Gassendi and others, that the formula cogito ergo sum' involves the unproved assumption, quod cogitat est.' There is neither premiss nor conclusion in the formula-it does not profess to be a syllogism, and our philosopher again and again denied its argumentative character; insisting on it that we may doubt the existence of our bodies, of the earth we tread upon, and of the heavens above us, that the belief in God may be a superstition, and in nature a delusion; but that it is impossible to doubt that we form such a judgment, to doubt, while we doubt, that we doubt.

Jules Simon correctly states the argument of the Discourse on Method' thus: The reason why Descartes assumed the "cogito ergo sum" as his groundwork, was that it appeared to him clearly and distinctly true, and hence everything that partook of this character was to be trusted as true on the same principle and with the same confidence.' But M. Simon insists upon it that the criterion' is only a general statement of the formula-that cogito ergo sum' is only an affirmation, in a psychologically concrete form, of the something of which the

criterion is a logical and general affirmation; viz. the validity of our faculties. But here he seems to us to have confounded two things-the assumption by Descartes of this formula, and the truth of the formula itself—the reason why he chose it as his groundwork, with the reason why it is, in itself, true. The two things appear to us essentially different: the one is a statement of a great fact that consciousness is the great source of information about self; and the other assures us that we can have as distinct a consciousness of other things as we have of self. Gassendi, Hobbes, and Locke, would have granted that, if we can obtain as certain a consciousness of any other thing as of selfexistence, then the Cartesian criterion would be the true canon of all philosophy; for it is not possible to deny our own existence in any words which are not unintelligible or absurd.

The able translator of the Discourse on Method,' who has been, we presume, one of the pupils of Sir W. Hamilton, has endeavoured to present in the form of a Reflective Analysis (pp. 28, 29), the way in which we arrive at this conviction of our existence from the phenomena of thought; although, we humbly submit, a similar process might possibly be framed by a second Sir W. Hamilton, for the intellectual generation of various elements of this process, and an infinite series of similar demonstrations given, for all its predecessors-all equally necessary for the full establishment of the cognition of that which it is impossible to deny.

It is well, however, to notice that Descartes felt the inadequacy of his criterion' for general use, until he had proved that he was not the sport of some malign spirit-some demon of darkness, whose pleasure it might be to confound human nature and make the evidence of our faculties and the validity even of our clearest perceptions questionable; and, though no demon ever could be supposed capable, by any process of deception, of making his own existence doubtful, yet it appeared to him that his criterion' was not sound, until he had demonstrated the perfections of the Deity. The paralogism involved in his meditations did not escape the acumen of his celebrated opponents, Mersenne and Arnauld. The existence of the Deity was proved by the force of the criterion;' but the validity of the criterion rested on the veracity and goodness of God. In his reply to Arnauld, he thus, however, expresses himself:

en

Qu'il n'est point tombé dans cette faute qu'on appelle cercle, disant que nous ne sommes assurés que les choses que nous concevons fort clairement, et fort distinctement, sont toutes vraies qu'a cause que Dieu existe, et que nous sommes assurés que Dieu existe, qu'a cause que nous concevons cela fort clairement, en faisant distinction des choses que nous concevons en effet, d'avec celles que nous nous

ressouvenons d'avoir autrefois fort clairement conçues. Car nous nous assurons que Dieu existe, en prêtant une attention actuelle aux raisons qui nous provent son existence.'-Réponses aux Quatrièmes Objections. By this modification of his first statement has Descartes disengaged his criterion of evidence from the demonstration of the being and perfections of God, giving to the evidence of the latter a value of its own. He has made the former rest upon two great propositions, depending for its character on the first, and for its validity on the second.

Inasmuch as every subsequent investigation of Descartes depends on the truth of the being of a God-infinitely wise, holy, powerful, and good-and as the philosophical structure which he reared rests on the philosophical proof of this position, he gave three demonstrations of this great proposition, which he repeated three several times in the Discourse on Method' in the Meditations' and the Principia.'

There are two axioms of great importance, which Descartes assumed in these arguments, and which may themselves be fiercely contested by all his opponents. The first is that ideas differ as much as the images of them in the mind, and those which represent substances have more objective reality than others and the second is nothing less than the great law of causation. Il doit pour le moins y avoir autant de réalité dans la cause efficient qu'il y a dans l'effet.' We may observe here, that all the Cartesians made a grievous mistake in not giving proper prominence to the active powers of man, and in virtually confounding the will with the decisions of the judgment and the desires of the soul. By doing this, the notion of causation and of force was driven, even in the theory of Descartes, into the background, and it was completely exterminated in those of Malebranche and Spinoza; but it is somewhat remarkable to find the principle of causation thus silently asserting its prerogative without a strictly logical summons, and underlying the argument of a philosopher who almost formally denounced it in the subsequent developments of his system. The first proof that our philosopher propounds of the being of God involves each of these axioms, and is seen to the greatest advantage in the third meditation. Ideas in the mind must answer to that of which they are the representations. Some ideas are merely the consequence of the relation of my mind to external objects, and I can account for them others are of my own creation-are due to my imagination or fancy, and are easily explicable. But I have within me the idea of God-of a substance, infinite, eternal, immutable, independent, omniscient, omnipotent-which I could not have created, because I am the reverse of all these things; which ex