executing successfully this chart or tree, a philosophical delineation of the natural progress of the mind may (according to him) furnish very useful lights; although he acknowledges that the results of the two undertakings cannot fail to differ widely in many instances the laws which regulate the generation of our ideas often interfering with that systematical order in the relative arrangement of scientific pursuits, which it is the purpose of the Encyclopedical Tree to exhibit.1

In treating of the first of these subjects, it cannot be denied that D'Alembert has displayed much ingenuity and invention; but the depth and solidity of his general train of thought may be questioned. On various occasions, he has evidently suffered himself to be misled by a spirit of false refinement; and on others, where probably he was fully aware of his inability to render the theoretical chain complete, he seems to have aimed at concealing from his readers the faulty links, by availing himself of those epigrammatic points, and other artifices of style, with which the genius of the French language enables a skilful writer to smooth and varnish over his most illogical transitions.

The most essential imperfections, however, of this historical sketch, may be fairly ascribed to a certain vagueness and indecision in the author's idea, with regard to the scope of his inquiries. What he has in general pointed at is to trace, from the theory of the Mind, and from the order followed by nature in the development of its powers, the successive steps by which

The true reason of this might perhaps have been assigned in simpler terms, by remarking that the order of invention is, in most cases, the reverse of that fitted for didactic communication. This observation applies not only to the analytical and synthetical processes of the individual, but to the progressive improvements of the species, when compared with the arrangements prescribed by logical method for conveying a knowledge of them to students. In an enlightened age, the sciences are justly

considered as the basis of the arts; and, in a course of liberal education, the former are always taught prior to the latter. But, in the order of invention and discovery, the arts preceded the sciences. Men measured land before they studied speculative geometry; and governments were established before politics were studied as a science. A remark somewhat similar is made by Celsus concerning the history of medicine: "Non medicinam rationi esse posteriorem, sed post medicinam inventam, rationem esse quæsitam."

to point out their most important defects,-defects which, I am nevertheless very ready to acknowledge, it is much more casy to remark than to supply. The critical strictures which, in the course of this discussion, I shall have occasion to offer on my predecessors, will, at the same time, account for my forbearing to substitute a new map of my own, instead of that to which the names of Bacon and D'Alembert have lent so great and so well-merited a celebrity; and may perhaps suggest a doubt, whether the period be yet arrived for hazarding again, with any reasonable prospect of success, a repetition of their bold experiment. For the length to which these strictures are likely to extend, the only apology I have to offer is the peculiar importance of the questions to which they relate, and the high autho- . rity of the writers whose opinions I presume to controvert.

Before entering on his main subject, D'Alembert is at pains to explain a distinction, which he represents as of considerable importance, between the Genealogy of the sciences, and the Encyclopedical arrangement of the objects of human knowledge.1 "In examining the former," he observes, "our aim is, by remounting to the origin and genesis of our ideas, to trace the causes to which the sciences owe their birth; and to mark the characteristics by which they are distinguished from each other. In order to ascertain the latter, it is necessary to comprehend, in one general scheme, all the various departments of study; to arrange them into proper classes; and to point out their mutual relations and dependencies." Such a scheme is sometimes likened by D'Alembert to a map or chart of the intellectual world; sometimes to a genealogical2 or encyclopedical tree, indicating the manifold and complicated affinities of those studies, which, however apparently remote and unconnected, are all the common offspring of the human understanding. For

Il ne faut pas confondre l'ordre Encyclopédique des connoissances humaines avec la Généalogie des Sciences."Avertissement, p. 7.

2

It is to be regretted that the epithet

genealogical should have been employed on this occasion, where the author's wish was to contradistinguish the idea denoted by it, from that historical view of the sciences to which the word genealogy had been previously applied.

executing successfully this chart or tree, a philosophical delineation of the natural progress of the mind may (according to him) furnish very useful lights; although he acknowledges that the results of the two undertakings cannot fail to differ widely in many instances the laws which regulate the generation of our ideas often interfering with that systematical order in the relative arrangement of scientific pursuits, which it is the purpose of the Encyclopedical Tree to exhibit.1

In treating of the first of these subjects, it cannot be denied. that D'Alembert has displayed much ingenuity and invention; but the depth and solidity of his general train of thought may be questioned. On various occasions, he has evidently suffered himself to be misled by a spirit of false refinement; and on others, where probably he was fully aware of his inability to render the theoretical chain complete, he seems to have aimed at concealing from his readers the faulty links, by availing himself of those epigrammatic points, and other artifices of style, with which the genius of the French language enables a skilful writer to smooth and varnish over his most illogical transitions.

The most essential imperfections, however, of this historical sketch, may be fairly ascribed to a certain vagueness and indecision in the author's idea, with regard to the scope of his inquiries. What he has in general pointed at is to trace, from the theory of the Mind, and from the order followed by nature in the development of its powers, the successive steps by which

1 The true reason of this might perhaps have been assigned in simpler terms, by remarking that the order of invention is, in most cases, the reverse of that fitted for didactic communication. This observation applies not only to the analytical and synthetical processes of the individual, but to the progressive improvements of the species, when compared with the arrangements prescribed by logical method for conveying a knowledge of them to students. In an enlightened age, the sciences are justly

considered as the basis of the arts; and, in a course of liberal education, the former are always taught prior to the latter. But, in the order of invention and discovery, the arts preceded the sciences. Men measured land before they studied speculative geometry; and governments were established before politics were studied as a science. A remark somewhat similar is made by Celsus concerning the history of medicine: "Non medicinam rationi esse posteriorem, sed post medicinam inventam, rationem esse quæsitam."

the curiosity may be conceived to have been gradually conducted from one intellectual pursuit to another; but, in the execution of this design, (which in itself is highly philosophical and interesting,) he does not appear to have paid due attention. to the essential difference between the history of the human species, and that of the civilized and inquisitive individual. The former was undoubtedly that which principally figured in his conceptions; and to which, I apprehend, he ought to have confined himself exclusively; whereas, in fact, he has so completely blended the two subjects together, that it is often impossible to say which of them was uppermost in his thoughts. The consequence is, that instead of throwing upon either those strong and steady lights which might have been expected from his powers, he has involved both in additional obscurity. This indistinctness is more peculiarly remarkable in the beginning of his Discourse, where he represents men in the earliest infancy of science, before they had time to take any precautions for securing the means of their subsistence, or of their safety, as philosophizing on their sensations,-on the existence of their own bodies, and on that of the material world. His Discourse, accordingly, sets out with a series of Meditations, precisely analogous to those which form the introduction to the philosophy of Descartes; meditations which, in the order of time, have been uniformly posterior to the study of external nature; and which, even in such an age as the present, are confined to a comparatively small number of recluse metaphysicians.

Of this sort of conjectural or theoretical history, the most unexceptionable specimens which have yet appeared, are indisputably the fragments in Mr. Smith's posthumous work on the History of Astronomy, and on that of the Ancient Systems of Physics and Metaphysics. That, in the latter of these, he may have occasionally accommodated his details to his own peculiar opinions concerning the object of Philosophy, may perhaps, with some truth, be alleged; but he must at least be allowed the merit of completely avoiding the error by which D'Alembert was misled; and even in those instances where he himself seems

to wander a little from the right path, of furnishing his successors with a thread, leading by easy and almost insensible steps, from the first gross perceptions of sense, to the most abstract refinements of the Grecian schools. Nor is this the only praise to which these fragments are entitled. By seizing on the different points of view from whence the same object was contemplated by different sects, they often bestow a certain degree of unity and of interest on what before seemed calculated merely to bewilder and to confound; and render the apparent aberrations and caprices of the understanding subservient to the study of its operations and laws.

To the foregoing strictures on D'Alembert's view of the origin of the sciences, it may be added, that this introductory part of his Discourse does not seem to have any immediate connexion with the sequel. We are led, indeed, to expect, that it is to prepare the way for the study of the Encylopedical Tree afterwards to be exhibited; but in this expectation we are completely disappointed;-no reference to it whatever being made by the author in the farther prosecution of his subject. It forms, accordingly, a portion of his Discourse altogether foreign to the general design; while, from the metaphysical obscurity which pervades it, the generality of readers are likely to receive an impression, either unfavourable to the perspicuity of the writer, or to their own powers of comprehension and of reasoning. It were to be wished, therefore, that instead of occupying the first pages of the Encyclopédie, it had been reserved for a separate article in the body of that work. There it might have been read by the logical student, with no small interest and advantage; for, with all its imperfections, it bears numerous and precious marks of its author's hand.

In delineating his Encyclopedical Tree, D'Alembert has, in my opinion, been still more unsuccessful than in the speculations which have been hitherto under our review. His veneration for Bacon seems, on this occasion, to have prevented him from giving due scope to his own powerful and fertile genius, and has engaged him in the fruitless task of attempting, by means of arbitrary definitions, to draw a veil over incurable