The only important proposition which I am able to extract from this jargon is, that, as extension and duration cannot be supposed to bear the most distant resemblance to any sensations of which the mind is conscious, the origin of these notions forms a manifest exception to the account given by Locke of the primary sources of our knowledge. This is precisely the ground on which Reid has made his stand against the scheme of Idealism; and I leave it to my readers to judge, whether it was not more philosophical to state, as he has done, the fact, in simple and perspicuous terms, as a demonstration of the imperfection of Locke's theory, than to have reared upon it a superstructure of technical mystery, similar to what is exhibited in the system of the German metaphysician. In justice, at the same time, to Kant's merits, I must repeat, that Dr. Reid would have improved greatly the statement of his argument against Berkeley, if he had kept as constantly in the view of his readers, as Kant has done, the essential distinction which I have endeavoured to point out between the mathematical affections of matter, and its primary qualities. Of this distinction he appears to have been fully aware himself, from a passage which I formerly quoted; but he has, in general, slurred it over in a manner which seemed to imply, that he considered them both as precisely of the same kind.

I shall only add farther, that the idea or conception of motion involves the ideas both of extension and of time.

En ecrivant, j'ai toujours taché de m'entendre, is an expression which Fontenelle somewhere uses, in speaking of his own literary habits. It conveys a hint not unworthy of the attention of authors; -but which I would not venture to recommend to that class who may aspire to the glory of founding new schools of philosophy.

That the idea of time might have been formed, without any ideas either of extension or of motion, is sufficiently obvious; but it is by no means equally clear, whether the idea of motion presupposes that of extension, or that of extension the idea of motion. The question relates to a fact of some curiosity in the natural history of the mind; having, for its object, to ascertain, with logical precision, the occasion on which the idea of extension is, in the first instance, acquired. But it is a question altogether foreign to the subject of the foregoing discussion. Whichever of the two conclusions we may adopt, the force of Reid's argument against Locke's principle will be found to remain undiminished.*

* See Note (L).

ESSAY THIRD.

ON THE INFLUENCE OF LOCKE'S AUTHORITY UPON THE PHILOSOPHICAL SYSTEMS WHICH PREVAILED IN FRANCE DURING THE LATTER PART OF THE EIGHTEENTH CENTURY.

THE account given by Locke of the origin of our ideas,

which furnished the chief subject of one of the foregoing Essays, has, for many years past, been adopted implicitly, and almost universally, as a fundamental and unquestionable truth, by the philosophers of France. It was early sanctioned in that country, by the authority of Fontenelle, whose mind was probably prepared for its reception, by some similar discussions in the works of Gassendi; at a later period, it acquired much additional celebrity, from the vague and exaggerated encomiums of Voltaire; and it has since been assumed, as the common basis of their respective conclusions concerning the history of the human understanding, by Condillac, Turgot, Helvetius, Diderot, D'Alembert, Condorcet, Destutt-Tracy, De Gerando, and many other writers of the highest reputation, at complete variance with each other, in the general spirit of their philosophical systems.*

Tous les philosophes François de ce siècle ont fait gloire de se ranger au nombre des disciples de Locke, et d'admettre ses principes. (De Gerando, de la Generation des Connoissances Humaines, p. 81.)

T

But although all these ingenious men have laid hold eagerly of this common principle of reasoning, and have vied with each other in extolling Locke for the sagacity which he has displayed in unfolding it, hardly two of them can be named who have understood it exactly in the same sense; and perhaps not one who has understood it precisely in the sense annexed to it by the author. What is still more remarkable, the praise of Locke has been loudest from those who seem to have taken the least pains to ascertain the import of his conclusions.

The mistakes so prevalent among the French philosophers on this fundamental question, may be accounted for, in a great measure, by the implicit confidence which they have reposed in Condillac, (whom a late author has distinguished by the title of the Father of Ideology), as a faithful expounder of Locke's doctrines; and by the weight which Locke's authority has thus lent to the glosses and inferences of his ingenious disciple. In the introduction to Condillac's Essay on the Origin of Human Knowledge, after remarking, that "a philosopher often announces the "truth, without being aware of it himself;" he adds, that "it seems to have been, by some accident of this sort, "that the Peripatetics were led to assume, as a principle, "that all our knowledge comes by the senses:-a princi"ple which they were so far from comprehending, that

none of them was able to unfold it in detail; and which "it was reserved for the moderns to bring to light, after "a long succession of ages."

"Bacon" (the same author continues) " was perhaps "the first who perceived it; having made it the ground

* Destutt-Tracy.

"work of a treatise, in which he gives excellent precepts "for the advancement of the sciences. The Cartesians "rejected it with contempt, because they formed their "judgment of it only upon the statement given by the "Peripatetics. At last, Locké laid hold of it, and has the "merit of being the first by whom its truth was demon"strated."

Of the meaning which Condillac annexed to this discovery of Locke, a sufficient estimate may be formed from the following sentence: "According to the system which "derives all our knowledge from the senses, nothing is "more easy than to form a precise notion of what is meant "by the word idea. Our ideas are only sensations, or por"tions abstracted from some sensation, in order to be con"sidered apart. Hence two sorts of ideas, the sensible, and "the abstract."* On other occasions, he tells us, that "all the operations of the understanding are only trans"formed sensations;† and that the faculty of feeling com

prehends all the other powers of the mind." I must acknowledge, for my own part, (with a very profound writer of the same country) "that these figurative expressions do not present to me any clear conceptions, "but, on the contrary, tend to involve Locke's principle " in much additional obscurity."‡

To how very great a degree this vague language of Condillac has influenced the speculations of his successors, will appear from some passages which I am now to pro

Traité des Systemes, p. 68.

Le jugement, la réflexion, les desirs, les passions, &c. ne sont que la sensation même qui se transforme differemment.-(Traité des Sensations, p. 4.)

78.

De Gerando, de la Generation des Connoissances Humaines, p.