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own part, at least, I must acknowledge that, in the passages formerly quoted from Cudworth, Leibnitz, and Harris, there are only a few peculiarities of hypothetical phraseology to which I am able to oppose any valid objection. The statements contained in them exhibit the whole truth blended with a portion of fiction; whereas, that to which they stand opposed, not only falls short of the truth but is contradicted by many of the most obvious and incontrovertible phenomena of the understanding.

On this, as on many other occasions, I have had much pleasure in recalling to recollection an observation of Leibnitz. "Truth is more generally diffused in the world than is commonly imagined; but it is too often disguised, and even corrupted, by an alloy of error, which conceals it from notice, or impairs its utility. By detecting it wherever it is to be found, among the rubbish which our predecessors have left behind them, we have not only the advantage resulting from the enlargement of our knowledge, but the satisfaction of substituting, instead of a succession of apparently discordant systems, a permanent and eternal philosophy (perennem quandam philosophiam,)-varying widely in its forms from age to age, yet never failing to exhibit a portion of truth, as its immutable basis."

The mistakes into which modern philosophers have fallen, on the important question now under our review, may, I think, be traced to a rash extension, or rather, to a total misapplication of Bacon's maxim, that all our knowledge is derived from experience. It is with this maxim, that Locke prefaces his theory concerning sensation and reflection, and it is from that preface that M. De Gerando borrows the motto of his own speculations upon the origin of our ideas. "Let us suppose," says Locke, "the mind to be, as we say, white paper, void of all characters, without any ideas; how comes it to be furnished? Whence comes it by that vast store which the busy and boundless fancy of man has painted on it, with an almost endless variety? Whence has it all the

See p. 71. et seq.

materials of reason and knowledge? To this I answer, in a word, from experience. In that all our knowledge is founded, and from that it ultimately derives itself."*

In what sense this celebrated maxim ought to be understood, I shall endeavour to show more particularly, if I should live to execute a plan which I have long meditated, of analysing the logical processes by which we are conducted to the different classes of truths, and of tracing the different kinds of evidence to their respective sources in our intellectual frame. For my present purpose, it is sufficient to observe, in general, that however universally the maxim may be supposed to apply to our knowledge of facts, whether relating to external nature or to our own minds, we must, nevertheless, presuppose the existence of some intellectual capacities or powers in that being by whom this knowledge is to be acquired; powers which are necessarily accompanied, in their exercise, with various simple notions, and various ultimate laws of belief, for which experience is altogether incompetent to account. How is it possible, for example to explain, upon this principle alone, by any metaphysical refinement, the operations of that reason which observes these phenomena; which records the past; which looks forward to the future; which argues synthetically from things known, to others which it has no opportunity of subjecting to the examination of the senses; and which has created a vast science of demonstrative truths, presupposing no knowledge whatever but of its own definitions and axioms? To say that, even in this science, the ideas of extension, of figure, and of quantity, are orignally acquired by our external senses, is a childish play upon words, quite foreign to the point at issue. Is there any one principle from which Euclid deduces a single consequence, the evidence of which rests upon experience, in the sense in

* It is a circumstance somewhat curious in Locke's Essay, that in no part of it are the works of Bacon quoted, or even his name mentioned. In taking notice of this, I do not mean to insinuate, that he has been indebted to Bacon for ideas which he was unwiling to acknowledge. On the contrary, I think that the value of his Essay would have been still greater than it is, if he had been better acquainted with Bacon's writings. The chief sources of Locke's philosophy, where he does not give scope to his own powerful and original genius, are to be found in Gassendi and Hobbes.

which that word is employed in the inductive logic? If there were, geometry would be no longer a demonstrative science.

Nor is this all. The truths in mathematics (admitting that of the hypotheses on which our reasonings proceed) are eternal and necessary; and, consequently, (as was early remarked, in opposition to Locke's doctrine) could never have been inferred from experience alone. "If Locke," says Leibnitz," had sufficiently considered the difference between truths which are necessary or demonstrative, and those which we infer from induction alone, he would have perceived, that necessary truths could only be proved from principles which command our assent by their intuitive evidence; inasmuch as our senses can inform us only of what is, not of what must necessarily be."*

But, even with respect to facts, there are certain limitations with which this .maxim must be received. Whence arises our belief of the continuance of the laws of nature? Whence our inferences from the past to the future? Not surely from experience alone. Although, therefore, it should be granted, as I readily do, that in reasoning concerning the future, we are entitled to assume no fact as a datum which is not verified by the experience of the past, (which, by the way, is the sole amount of Bacon's aphorism), the question still remains, what is the origin of our confident belief, that past events may be safely assumed as signs of those which are yet to happen? The case is precisely the same with the faith we repose in human testimony; nor would it be at all altered, if, in the course of our past experience, that testimony had not once deceived us. Even, on that supposition, the question would still recur, whence is it we conclude, that it will not deceive us in future? or (what comes nearly to the same thing) that we give any credit to the narratives of men who existed two thousand years ago? No proposition, surely, can be more evident than

"Si Lockius discrimen inter veritates necessarias seu demonstratione perceptas, et eas quæ nobis solâ inductione utcunque innotescunt, satis considerâsset,-animadvertisset, necessarias non posse comprobari, nisi ex principiis menti insitis; cum sensus quidem doceant quid fiat, sed non quid necessario fiat."-Tom. V. p. 358. (Edit. Dutens.)

this, that experience, in the acceptation in which Locke and his followers profess to understand it, can inform us of nothing but what has actually fallen under the retrospect of memory.-Of the truth and importance of these considerations, no philosopher seems to have been fully aware, previous to Mr. Hume. "As to past experience," he observes, "it can be allowed to give direct and certain information of those precise objects only, and that precise period of time, which fell under its cognizance; but why this experience should be extended to future times, and to other objects, this is the main question on which I would insist." * What is the proper answer to this question is of no moment to our present argument. It is sufficient, if it be granted, that experience alone does not afford an adequate explanation of the fact.

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In concluding this essay, it may not be altogether useless to remark the oppsite errors which the professed followers of Bacon have committed, in studying the phenomena of matter, and those of mind. In the former where Bacon's maxim seems to hold wihout any limitation, they have frequently shown a disposition to stop short in its application; and to consider certain physical laws (such as the relation between the force of gravitation, and the distance of the gravitating bodies), as nessary truths, or truths which admitted of a proof, a priori; while, on the other hand, in the science of mind, where the same principle, when carried beyond certain limits, involves a manifest absurdity, they have attempted to extend it, without one single exception, to all the primary elements of our knowledge, and even to the generation of those reasoning faculties which form the characteristical attributes of our species.

* See Hume's essay entitled Sceptical Doubts, &c.

ESSAY FOURTH.

ON THE METAPHYSICAL THEORIES OF HARTLEY, PRIESTLEY,

AND DARWIN.

WHEN I hinted, in the preceding essay, that the doctrines prevalent in this country, with respect to the origin of our knowledge, were, in general, more precise and just than those adopted by the disciples of Condillac, I was aware that some remarkable exceptions might be alleged to the universality of my observations. Of those, indeed, who, in either part of the united kingdom, have confined their researches to the Philosophy of the Human Mind, properly so called, I do not recollect any individual of much literary eminence, who has carried Locke's principle to such an extravagant length as Diderot and Helvetius; but, from that class of our authors, who have, of late years, been attempting to found a new school, by jumbling together scholastic metaphysics and hypothetical physiology, various instances might be produced of theorists, whose avowed opinions on this elementary question, not only rival, but far surpass that of the French Materialists, in point of absurdity.

Among the authors just alluded to, the most noted are Hartley, Priestley, and Darwin; all of whom, notwithstanding the differences among them on particular points, agree nearly in their conclusions concerning the sources of our ideas. The first of these, after telling us, that "all our internal feelings, excepting our sensations, may be called ideas ;-that the ideas which resemble sensations may be called ideas of sensation, and all the rest intellectual ideas; "-adds, "that the ideas of sensation are the elements of which all the rest are compounded." In another passage he expresses his hopes, that, "by pursuing and perfecting the doctrine of association, he may some time or other, be enabled to analyse all that vast

* Hartley on Man, 4th edition, p. 2. of the Introduction. VOL. IV.

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