on a crusade against their religion, he, as I have already observed, encouraged it in other countries; and, though a bishop of the Catholic church, he did not hesitate, by treaties, by money, and by force of arms, to support the Protestants against the House of Austria, maintain the Lutherans against the Emperor of Germany, and uphold the Calvinists against the King of Spain.

I have thus endeavoured to draw a slight, though, I trust, a clear outline, of the events which took place in France during the reign of Louis XIII., and particularly during that part of it which included the administration of Richelieu. But such occurrences, important as they are, only formed a single phase of that larger development which was now displaying itself in nearly every branch of the national intellect. They were the mere political expression of that bold and sceptical spirit which cried havoc to the prejudices and superstitions of men. For, the government of Richelieu was successful, as well as progressive; and no government can unite these two qualities, unless its measures harmonize with the feelings and temper of the age. Such an administration, though it facilitates progress, is not the cause of it, but is rather its measure and symptom. The cause of the progress lies far deeper, and is governed by the general tendency of the time. And as the different tendencies observable in successive generations depend on the difference in their knowledge, it is evident, that we can only understand the working of the tendencies, by taking a wide view of the amount and character of the knowledge. To comprehend, therefore, the real nature of the great advance made during the reign of Louis XIII., it becomes necessary that I should lay before the reader some evidence respecting those higher and more important facts, which historians are apt to neglect, but without which the study of the past is an idle and trivial pursuit, and history itself a barren field, which, bearing no fruit, is unworthy of the labour that is wasted on the cultivation of so ungrateful a soil.

It is, indeed, a very observable fact, that while Richelieu, with such extraordinary boldness, was secularizing the whole system of French politics, and by his disregard of ancient interests, was setting at naught the most ancient traditions, a course precisely similar was being pursued, in a still higher department, by a man greater than he; by one, who, if I may express my own opinion, is the most profound among the many eminent thinkers France has produced. I speak of Réné Descartes, of whom the least that can be said is, that he effected a revolution more decisive than has ever been brought about by any other single mind. With his mere physical discoveries we are not now concerned, because in this Introduction I do not pretend to trace the pro

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gress of science, except in those epochs which indicate a new turn in the habits of national thought. But I may remind the reader, that he was the first who successfully applied algebra to geometry:201 that he pointed out the important law of the sines; 202 that in an age in which optical instruments were extremely imperfect, he discovered the changes to which light is subjected in the eye by the crystalline lens ;203 that he directed attention to the consequences resulting from the weight of the atmosphere ;204

201 Thomas (Eloge, in Euvres de Descartes, vol. i. p. 32) says, "cet instrument, c'est Descartes qui l'a créé; c'est l'application de l'algèbre à la géométrie." And this, in the highest sense, is strictly true; for although Vieta and two or three others in the sixteenth century had anticipated this step, we owe entirely to Descartes the magnificent discovery of the possibility of applying algebra to the geometry of curves, he being undoubtedly the first who expressed them by algebraic equations. See Montucla, Hist. des Mathemat. vol. i. pp. 704, 705, vol. ii. p. 120, vol. iii. p. 64.

202 The statements of Huygens and of Isaac Vossius to the effect that Descartes had seen the papers of Snell before publishing his discovery, are unsupported by any direct evidence; at least none of the historians of science, so far as I am aware, have brought forward any. So strong, however, is the disposition of mankind at large to depreciate great men, and so general is the desire to convict them of plagiarism, that this charge, improbable in itself, and only resting on the testimony of two envious rivals, has been not only revived by modern writers, but has been, even in our own time, spoken of as a well-established and notorious fact! The flimsy basis of this accusation is clearly exposed by M. Bordas Demoulin, in his valuable work Le Cartesianisme, Paris, 1843, vol. ii. pp. 9-12; while, on the other side of the question, I refer with regret to Sir D. Brewster on the Progress of Optics, Second Report of British Association, pp. 309, 310; and to Whewell's Hist. of the Inductive Sciences, vol. ii. pp. 379, 502, 503.

203 See the interesting remarks of Sprengel (Hist. de la Médecine, vol. iv. pp. 271, 272), and Euvres de Descartes, vol. iv. pp. 371 seq. What makes this the more observable is, that the study of the crystalline lens was neglected long after the death of Descartes, and no attempt made for more than a hundred years to complete his views by ascertaining its intimate structure. Indeed, it is said (Thomson's Animal Chemistry, p. 512) that the crystalline lens and the two humours were first analyzed in 1802. Compare Simon's Animal Chemistry, vol. ii. pp. 419-421; Henle, Traité d'Anatomie, vol. i. p. 357; Lepelletier, Physiologie Médicale, vol. iii. p. 160; Mayo's Human Physiol. p. 279; Blainville, Physiol. comparée, vol. iii. pp. 325-328; none of whom refer to any analysis earlier than the nineteenth century. I notice this partly as a contribution to the history of our knowledge, and partly as proving how slow men have been in following Descartes, and in completing his views; for, as M. Blainville justly observes, the chemical laws of the lens must be understood, before we can exhaustively generalize the optical laws of its refraction; so that, in fact, the researches of Berzelius on the eye are complemental to those of Descartes. The theory of the limitation of the crystalline lens according to the descending scale of the animal kingdom, and the connexion between its development and a general mcrease of sensuous perception, seem to have been little studied; but Dr. Grant (Comparative Anatomy, p. 252) thinks that the lens exists in some of the rotifera; while in regard to its origin, I find a curious statement in Müller's Physiology, vol. i. p. 450, that after its removal in mammals, it has been reproduced by its matrix, the capsule. (If this can be relied on, it will tell against the suggestion of Schwann, who supposes, in his Microscopical Researches, 1847, pp. 87, 88, that its mode of life is vegetable, and that it is not "a secretion of its capsule.") As to its probable existence in the hydrozoa, see Rymer Jones's Animal Kingdom, 1855, p. 96, “regarded either as a crystalline lens, or an otolithe;" and as to its embryonic develop ment, see Burdach, Traité de Physiologie, vol. iii. pp. 435-438.

204 Torricelli first weighed the air, in 1643. Brande's Chemistry, vol. i. p. 360; Leslie's Natural Philosophy, p. 419: but there is a letter from Descartes, written as early as 1631, "où il explique le phénomène de la suspension du mercure dans un

and that he, moreover, detected the causes of the rainbow,205 that singular phenomenon, with which, in the eyes of the vulgar, some theological superstitions are still connected.206 At the same time, and as if to combine the most varied forms of excellence, he is not only allowed to be the first geometrician of the age,207 but, by the clearness and admirable precision of his style, he became one of the founders of French prose.208 And although he was constantly engaged in those lofty inquiries into the nature of the human mind, which can never be studied without wonder, I had almost said can never be read without awe, he combined with them a long course of laborious experiment upon the animal frame, which raised him to the highest rank among the anatomists of his time.209 The great discovery made by Harvey of the circulation of the blood, was neglected by most of his contemporaries ;210 but it was at once recognized by Descartes, who tuyau fermé par en haut, en l'attribuant au poids de la colonne d'air élevée jusqu'au delà des nues." Bordas Demoulin, le Cartesianisme, vol. i. p. 311. And Montucla (Hist. des Mathemat. vol. ii. p. 205) says of Descartes," nous avons des preuves que ce philosophe reconnut avant Torricelli la pesanteur de l'air." Descartes himself says, that he suggested the subsequent experiment of Pascal. Euvres de Descartes,

vol. x. pp. 344, 351.

205 Dr. Whewell, who has treated Descartes with marked injustice, does nevertheless allow that he is "the genuine author of the explanation of the rainbow." Hist. of the Induc. Sciences, vol. ii. pp. 380, 384. See also Boyle's Works, vol. iii.

p. 189; Thomson's Hist. of the Royal Society, p. 364; Hallam's Lit. of Europe, vol. iii. p. 205; Euvres de Descartes, vol. i. pp. 47, 48, vol. v. pp. 265-284. On the theory of the rainbow as known in the present century, see Kaemtz, Course of Meteorology, pp. 440-445; and Forbes on Meteorology, pp. 125-130, in Report of British Association for 1840. Compare Leslie's Natural Philosophy, p. 531; Pouillet, Elémens de Physique, vol. ii. p. 788.

206 The Hebrew notion of the rainbow is well known; and for the ideas of other nations on this subject, see Prichard's Physical History of Mankind, vol. v. pp. 154, 176; Kames's Sketches of the History of Man, vol. iv. p. 252, Edinb. 1788; and Burdach's Physiologie, vol. v. pp. 546, 547, Paris, 1839.

207 Thomas calls him "le plus grand géomètre de son siècle." Euvres de Descartes, vol. i. p. 89. Sir W. Hamilton (Discussions on Philosophy, p. 271) says, "the greatest mathematician of the age;" and Montucla can find no one but Plato .to compare with him: "On ne sauroit donner une idée plus juste de ce qu'a été l'époque de Descartes dans la géométrie moderne, qu'en la comparant à celle de Platon dans la géométrie ancienne. . . . . De même enfin que Platon prépara par sa découverte celles des Archimède, des Apollonius, &c., on peut dire que Descartes a jetté les fondemens de celles qui illustrent aujourd'hui les Newton, les Leibnitz, &c." Montucla, Hist. des Mathémat. vol. ii. p. 112.

208 "Descartes joint encore à ses autres titres, celui d'avoir été un des créateurs de notre langue." Biog. Univ. vol. xi. p. 154. Sir James Mackintosh (Dissert. on Ethical Philos. p. 186) has also noticed the influence of Descartes in forming the style of French writers; and I think that M. Cousin has somewhere made a similar remark.

209 Thomas says, "Descartes eut aussi la gloire d'être un des premiers anatomistes de son siècle." Euvres de Descartes, vol. i. p. 55; see also p. 101. In 1639, Descartes writes to Mersenne (Euvres, vol. viii. p. 100) that he had been engaged "depuis onze ans" in studying comparative anatomy by dissection. Compare p. 174, and vol. i. pp. 175-184.

"It was

210 Dr. Whewell (Hist. of the Inductive Sciences, vol. iii. p. 440) says, for the most part readily accepted by his countrymen; but that abroad it had to

212

made it the basis of the physiological part of his work on Man.211 He likewise adopted the discovery of the lacteals by Aselli," which, like every great truth yet laid before the world, was, at its first appearance, not only disbelieved, but covered with ridicule, 213

214

These things might have been sufficient to rescue even the physical labours of Descartes from the attacks constantly made on them by men who either have not studied his works, or else, having studied them, are unable to understand their merit. But the glory of Descartes, and the influence he exercised over his age, do not depend even on such claims as these. Putting them aside, he is the author of what is emphatically called Modern Philosophy. He is the originator of that great system and method of metaphysics, which, notwithstanding its errors, has the undoubted merit of having given a wonderful impulse to the European mind, and communicated to it an activity which has been been made available for other purposes of a different character. Besides this, and superior to it, there is another obligation which we are under to the memory of Descartes. He deserves encounter considerable opposition." For this no authority is quoted; and yet one would be glad to know who told Dr. Whewell that the discovery was readily accepted. So far from meeting in England with ready acceptance, it was during many years almost universally denied. Aubrey was assured by Harvey that in conse quence of his book on the Circulation of the Blood he lost much of his practice, was believed to be crack brained, and was opposed by "all the physicians." Aubrey's Letters and Lives, vol. ii. p. 383. Dr. Willis (Life of Harvey, p. xli. in Harvey's Works, edit. Sydenham Society, 1847) says, "Harvey's views were at first rejected almost universally." Dr. Elliotson (Human Physiology, p. 194) says, "His imme diate reward was general ridicule and abuse, and a great diminution of his practice." Broussais (Examen des Doctrines Médicales, vol. i. p. vii.) says, "Harvey passa pour fou quand il annonça la découverte de la circulation." Finally, Sir William Temple, who belongs to the generation subsequent to Harvey, and who, indeed, was not born until some years after the discovery was made, mentions it in his works in such a manner as to show that even then it was not universally received by educa ted men. See two curious passages, which have escaped the notice of the historians of physiology, in Works of Sir W. Temple, vol. iii. pp. 293, 469, 8vo, 1814.

Taken by Descartes as the basis of his physiology, in his work on Man." Whewell's Hist. of the Induc. Sciences, vol. iii. p. 441. "Réné Descartes se déclara un des premiers en faveur de la doctrine de la circulation." Renouard, Hist. de la Médecine, vol. ii. p. 163. See also Bordas Demoulin, le Cartesianisme, vol. ii. p. 324; and Euvres de Descartes, vol. i. pp. 68, 179, vol. iv. pp. 42, 449, vol. ix. pp. 159, 332. Compare Willis's Life of Harvey, p. xlv. in Harvey's Works.

212 Les veines blanches, dites lactées, qu'Asellius a découvertes depuis peu dans le mésentère." De la Formation du Fatus, sec. 49, in Euvres de Descartes, vol. iv. p. 483.

213 Even Harvey denied it to the last. Sprengel, Hist. de la Méd. vol. iv. pp. 203, 204. Compare Harvey's Works, edit. Sydenham Soc. pp. 605, 614.

214 M. Cousin (Hist. de la Philos. II. série, vol. i. p. 39) says of Descartes, 66 son premier ouvrage écrit en français est de 1637. C'est donc de 1637 que date la phi losophie moderne." See the same work, I. série, vol. iii. p. 77; and compare Stew art's Philos. of the Mind, vol. i. pp. 14, 529, with Eloge de Parent, in Œuvres de Fontenelle, Paris, 1766, vol. v. p. 444, and vol. vi. p. 318: Cartésien, ou, si l'on veut, philosophe moderne."

แ

the gratitude of posterity, not so much on account of what he built up, as on account of what he pulled down. His life was one great and successful warfare against the prejudices and traditions of men. He was great as a creator, but he was far greater as a destroyer. In this respect he was the true successor of Luther, to whose labours his own were the fitting supplement. He completed what the great German reformer had left undone.215 He bore to the old systems of philosophy precisely the same relation that Luther bore to the old systems of religion. He was the great reformer and liberator of the European intellect. To prefer, therefore, even the most successful discoverers of physical laws, to this great innovator and disturber of tradition, is just as if we should prefer knowledge to freedom, and believe that science is better than liberty. We must, indeed, always be grateful to those eminent thinkers, to whose labours we are indebted for that vast body of physical truths which we now possess. But, let us reserve the full measure of our homage for those far greater men, who have not hesitated to attack and destroy the most inveterate prejudices; men who, by removing the pressure of tradition, have purified the very source and fountain of our knowledge, and secured its future progress, by casting off obstacles in presence of which progress was impossible.2

216

It will not be expected, perhaps it will hardly be desired, that I should enter into a complete detail of the philosophy of Descartes; a philosophy which, in England at least, is rarely studied, and, therefore, is often attacked. But it will be necessary to give such an account of it as will show its analogy with the anti-theological policy of Richelieu, and will thus enable us to see the full extent of that vast movement which took place in France before the accession of Louis XIV. By this means, we shall be able to understand how the daring innovations of the great minister were so successful, since they were accompanied and reinforced by corresponding innovations in the national intellect; thus affording an additional instance of the way in which

215"Descartes avait établi dans le domaine de la pensée l'indépendance absolue de la raison; il avait déclaré à la scolastique et à la théologie que l'esprit de l'homme ne pouvait plus relever que de l'évidence qu'il aurait obtenue par lui-même. Ce que Luther avait commencé dans la religion, le génie français si actif et si prompt l'importait dans la philosophie, et l'on peut dire à la double gloire de l'Allemagne et de la France que Descartes est le fils aîné de Luther." Lerminier, Philos. du Droit, vol. ii. p. 141. See also, on the philosophy of Descartes as a product of the Reformation, Ward's Ideal of a Christian Church, p. 498.

216 For, as Turgot finely says, "ce n'est pas l'erreur qui s'oppose aux progrés de la vérité. Ce sont la mollesse, l'entêtement, l'esprit de routine, tout ce qui porte à l'inaction." Pensées, in Œuvres de Turgot, vol. ii. p. 343.