If the foregoing remarks are well founded, they lead to the correction of an oversight which occurs in the ingenious and elegant sketch of the History of Astronomy, lately published among the posthumous works of Mr. Smith; and which seems calculated to keep out of view, if not entirely to explode, that essential distinction which I have been endeavouring to establish, between the inductive logic of Bacon's followers, and the hypothetical theories of their predecessors.

"Philosophy," says Mr. Smith, "is the science of the connecting principles of nature. Nature, after the largest experience that common observation can acquire, seems to abound with events which appear solitary and incoherent with all that go before them which, therefore, disturb the easy movement of the imagination; which make its ideas succeed each other, if one may say so, by irregular starts and sallies; and which thus tend, in some measure, to introduce a confusion, and distraction, and giddiness of mind. Philosophy, by representing the invisible chains which bind together all these disjointed objects, endeavours to introduce order into this chaos of jarring and discordant appearances; to allay this tumult of the imagination; and to restore it, when it surveys the great revolutions of the universe, to that tone of tranquillity and composure, which is both most agreeable in itself, and most suitable to its nature. Philosophy, therefore, may be regarded as one of those arts which address themselves to the imagination, by rendering the theatre of nature a more coherent, and, therefore, a more magnificent spectacle, than otherwise it would have appeared to be."

That this is one of the objects of philosophy, and one of the advantages resulting from it, I very readily admit. But, surely, it is not the leading object of that plan of inductive investigation which was recommended by Bacon, and which has been so skilfully pursued by Newton. Of all philosophical systems, indeed, hypothetical or legitimate, it must be allowed, that to a certain degree, they both please the imagination and assist the memory, by introducing order and arrangement among facts, which had the appearance, before, of being alto

gether unconnected and isolated. But it is the peculiar and exclusive prerogative of a system fairly obtained by the method of induction, that, while it enables us to arrange facts already known, it furnishes the means of ascertaining, by synthetic reasoning, those which we have no access to examine by direct observation. The difference, besides, among hypothetical theories, is merely a difference of degree, arising from the greater or less ingenuity of their authors; whereas legitimate theories are distinguished from all others radically and essentially; and, accordingly, while the former are liable to perpetual vicissitudes, the latter are as permanent as the laws which regulate the order of the universe.

Mr. Smith himself has been led, by this view of the object of philosophy, into expressions concerning the Newtonian discoveries, which seem to intimate, that, although he thought them far superior, in point of ingenuity, to any thing the world had seen before, yet that he did not consider them as so completely exclusive of a still happier system in time to come, as the Newtonians are apt to imagine. "The system of Newton," he observes, "now prevails over all opposition, and has advanced to the acquisition of the most universal empire that was ever established in philosophy. His principles, it must be acknowledged, have a degree of firmness and solidity that we should in vain look for in any other system. The most sceptical cannot avoid feeling this. They not only connect together most perfectly all the phenomena of the heavens which had been observed before his time; but those also which the persevering industry and more perfect instruments of later astronomers have made known to us, have been either easily and immediately explained by the application of his principles, or have been explained in consequence of more laborious and accurate calculations from these principles, than had been instituted before. And even we, while we have been endeavouring to represent all philosophical systems as mere inventions of the imagination, to connect together the otherwise disjointed and discordant phenomena of nature, have insensibly been drawn in to make use of language expressing the con

necting principles of this one, as if they were the real chains which nature makes use of, to bind together her several operations."

If the view which I have given of Lord Bacon's plan of investigation be just, it will follow, That the Newtonian theory of gravitation can, in no respect whatever, admit of a comparison with those systems which are, in the slightest degree, the offspring of imagination; inasmuch as the principle employed to explain the phenomena is not a hypothesis, but a general fact established by induction; for which fact we have the very same evidence as for the various particulars comprehended under it. The Newtonian theory of gravitation, therefore, and every other theory which rests on a similar basis, is as little liable to be supplanted by the labors of future ages, as the mathematical conclusions of Euclid and Archimedes. The doctrines which it involves may be delivered in different, and perhaps less exceptionable forms; but, till the order of the universe shall be regulated by new physical laws, their substance must for ever remain essentially the same. On the chains, indeed, which nature makes use of to bind together her several operations, Newton has thrown no light whatever; nor was it the aim of his researches to do so. The subjects of his reasonings were not occult connexions, but particular phenomena, and general laws; both of them possessing all the evidence which can belong to facts ascertained by observation and experiment. From the one or the other of these all his inferences, whether analytical or synthetical, are deduced: Nor is a single hypothesis involved in his data, excepting the authority of that Law of Belief which is tacitly and necessarily assumed in all our physical conclusions,-The stability of the order of nature.

SECTION II.

Continuation of the Subject.-The Induction of Aristotle compared with that of Bacon.

In this section I intend to offer a few slight remarks upon an assertion which has been hazarded with some confidence in various late publications, that the method of investigation, so much extolled by the admirers of Lord Bacon, was not unknown to Aristotle.-It is thus very strongly stated by the ingenious author of a memoir in the Asiatic Researches.*

"From some of the extracts contained in this paper, it will appear, 1st, That the mode of reasoning by induction, illustrated and improved by the great Lord Verulam in his Organum Novum, and generally considered as the cause of the rapid progress of science in later times, was perfectly known to Aristotle, and was distinctly delineated by him, as a method of investigation that leads to certainty or truth: and 2dly, That Aristotle was likewise perfectly acquainted, not merely with the form of induction, but with the proper materials to be employed in carrying it on-facts and experiments. We are therefore led to conclude, that all the blame of confining the human mind for so long a time in chains, by the force of syllogism, cannot be fairly imputed to Aristotle; nor all the merit of enlarging it, and setting it free, ascribed to Lord Verulam."

The memoir from which this passage is copied, consists of extracts translated (through the medium of the Persian) from an Arabic treatise entitled the Essence of Logic. When it was first presented to the Asiatic Society, the author informs us, that he was altogether ignorant of the coincidence of his own conclusions with those of Dr. Gillies; and he seems to have received much satisfaction from the subsequent perusal of the proofs alleged in support of their common opinion by that learned writer. "From the perusal of this wonderful book," Dr. Gillies's exposition of the Ethics and Politics of

* Asiatic Researches, Vol. VIII. p. 89, 90. London Edition.

Aristotle, "I have now the satisfaction to discover, that the conjectures I had been led to draw from these scanty materials, are completely confirmed by the opinion of an author, who is probably better qualified than any preceding commentator on Aristotle's works, to decide on this subject." *

It is observed by Bailly, in his History of Astronomy, that, although frequent mention is made of attraction in the writings of the ancients, we must not therefore "conclude that they had any precise or just idea of that law into which Newton has resolved the phenomena of the planetary revolutions. To their conceptions, this word presented the notion of an occult sympathy between different objects; and if any of them extended it from the descent of terrestrial bodies to explain the manner in which the moon was retained in her orbit, it was only an exhibition upon a larger scale of the popular error." The same author has remarked, on a different occasion, that, in order to judge of the philosophical ideas entertained at a particular period, it would be necessary to possess the dictionary of the age, exhibiting the various shades of meaning derived from fashion or from tradition. "The import of words," he adds, changes with the times: their signification enlarging with the progress of knowledge. Languages are every moment perishing in detail from the variations introduced by custom: they grow old like those that speak them, and, like them, gradually alter their features and their form." +

If this observation be just, with respect to the attraction of the ancients, when compared with the attraction of Newton, it will be found to apply with still greater force to the induction of Aristotle,§ considered in contrast with the induction of Bacon.

It is well known to those who are at all conversant with Bacon's writings, that, although he borrowed many expressions from the scholastic phraseology then in

* Asiatic Researches, Vol. VIII. p. 89, 90. London Edition. Hist. de l'Astronomie Moderne, Tome II, p. 555, 556.

Ibid. p. 184.

'Exaywyn. Translated Inductio by Cicero.