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senses, or else such as are perceived by attending to the passions and operations of the mind; or, lastly, ideas formed by help of memory and imagination, either compounding, dividing, or barely representing those originally perceived in the foresaid ways.Light and colours, heat and cold, extension and figure, in a word, the things we see and feel, what are they but so many sensations, notions, ideas, or impressions on the senses; and is it possible to separate, even in thought, any of these from perception? For my own part, I might as easily divide a thing from itself." Mr. Hume again asserts, that all our ideas are nothing but copies of our impressions; or, in other words, that it is impossible for us to think of any thing that we have not antecedently felt, either by our external or our internal senses. He assures us, that nothing can be present to the mind but an image or impression: and that the senses are only the inlets through which these images are conveyed, without being able to produce any immediate intercourse between the mind and the object.

It admits of no doubt, that Mr. Locke himself conceived these images, or copies of impressions, to be the immediate objects of thought; all our knowledge of the material world being obtained by their intervention. He enters regularly into the inquiry, How bodies produce ideas in us? and "that," says he, "is manifestly by impulse, the only way we can conceive bodies to operate in." "If then," he continues, "external objects be not united to our minds when they produce ideas in it, and yet we perceive these original qualities in such of them as singly fall under our senses, it is evident that some motion must be thence continued by our nerves or animal spirits, or by some parts of our bodies, to the brain, or the seat of sensation, there to produce in our minds the particular ideas we have of them. And since the extension, figure, number, and motion of bodies, of an observable bigness, may be perceived at a distance by the sight, it is evident some singly imperceptible bodies must come from them to the eyes, and thereby convey to the brain some motion which produces these ideas, which we have of them in us."

Having stated the distinction between the primary and the secondary qualities of matter, he proceeds thus:"From whence I think it easy to draw this observation, that the ideas of primary qualities of bodies are resemblances of them, and their patterns do really exist in the bodies themselves; but the ideas produced in us by these secondary qualities have no resemblance of them at all." The import which he here attaches to the word re semblance, as applied to our ideas of primary qualities, may be gathered from the following sentence, where he gives an account of the difference between them and our ideas of secondary quali

ties. "Flame is denominated hot and light; snow, white and cold; and manna, white and sweet; from the ideas they produce in us; which qualities are commonly thought to be the same in those bodies that those ideas are in us, the one the perfect resemblance of the other, as they are in a mirror; and it would by most men be judged very extravagant, if one should say otherwise." "Methinks," he says, in another place," the understanding is not much unlike a closet, wholly shut from light, with only some little openings left, to let in external visible resemblances or ideas of things without; would the pictures coming into a dark room but stay there, and lie so orderly as to be found upon occasion, it would very much resemble the understanding of a man, in reference to all objects of sight and the ideas of them."

We have given these extracts in order to show, that Locke, Berkeley, and Hume held, to its full extent, the ancient doctrine in regard to perception, and believed that the only intercourse which the mind is capable of maintaining, with external nature, is that which takes place in the sensorium through the medium of ideas; consequently, that the human soul does not contemplate external objects themselves, but merely their images, conveyed to it by the nerves, or some other part of the bodily mechanism; and hence that these authors lent the support of their powerful talents to the conclusion already so often mentioned, namely, that we can possess no evidence for the existence of the material world, but only for the existence of ideas and sensations in our minds.

It was the object, of Dr. Reid's first and ablest work to undermine the foundations of that theory, which, after having reigned in the schools two thousand years, bewildered the speculations of Locke, Clarke, and Newton; and afterwards supplied to Berkeley and Hume the materials of a system which shook all the principles of human knowledge, and took away from the deductions of intellect, and even from the instinctive impressions of natural belief, the confidence and certainty which they have always been found to confer upon every sound understanding. The northern philosopher undertook to prove, that the human mind perceives, not merely the ideas of things, but the very things themselves; that it is not simply the idea of hardness which follows the touching of a table or piece of metal, but the actual sensation of a hard and extended substance, external to the mind: such sensation being always accompanied with the belief, that the object to which it refers has a distinct and separate existence, independently of our impression of its qualities. According to him, when we look at a house, it is the house itself which we perceive, and not merely the idea of the house, situated in what Locke would

have called the dark closet of the mind. In a word, our perceptions bear a direct reference to the properties of matter, and not to the images of these properties in the sensorium; and as all our perceptions are accompanied with an instinctive belief, that the objects whence they arise, have an existence independent of their relation to our minds, we enjoy the most satisfactory evidence that the case admits of, that there is around us a system of material created substances.

The labours of Reid put an end to the idealism of Berkeley and Hume. He showed, that the principles of their system were not only unsupported by any proof, but contrary to incontestible facts; nay, that they were utterly inconceivable from the manifest inconsistencies and absurdities which they involved.

Dr. Priestley, it is well known, took the field against the Scottish philosopher; not with the intention of proving that his views were dangerous or fallacious, but to deprive him of the merit of originality where his opinions appeared of any value, and to convict him of ignorance in regard to many of the tenets which he had impugned. Not content with tracing a close resemblance between the "First Truths" of Le Pere Buffier, and the fundamental principles of belief maintained by Dr. Reid, he asserted, that the latter had been all along waging war with a phantom of his own creation, for that the doctrines which he combatted were never seriously maintained by any philosopher, either ancient or modern, Before our author had rested so much upon this argument," says Dr. Priestley, "it behoved him, I think, to have examined the strength of it a little more carefully than he seems to have done; for he appears to me to have suffered himself to be misled in the very foundation of it, merely by philosophers happening to call ideas the images of external things; as if this was not known to be a figurative expression, denoting, not that the actual shapes of things were delineated in the brain or upon the mind, but only that impressions of some kind or other were conveyed to the mind by means of the organs of sense, and their corresponding nerves, and that between these impressions and the sensations existing in the mind, there is a real and necessary, though at present an unknown, connection."

This statement betrays much ignorance or unfairness. It is impossible to open the volumes of Berkeley or of Hume without perceiving, at the first glance, that the account now given of the word idea is at complete variance with their ordinary use of the same term. Do not all the reasonings which were deduced by these writers from Locke's philosophy, against the independent existence of the material world, hinge on that very principle which Dr. Priestley affects to consider as merely an accidental

mode of speaking, never meant to be understood literally? Had the metaphysicians who wrote prior to the time of Reid, used the terms ideas and images as mere figurative expressions, his work would indeed have proved an absurd and most unseasonable interruption to the progress of sound philosophy; but so far was that from being the case, it is universally admitted among competent judges, that the ideas of Descartes and his successors were little else (at least so far as perception is concerned) than a new name for the species of the schoolmen;-the various ambiguities connected with the word idea, says Mr. Stewart, having probably contributed not a little to shelter the doctrine, in its more modern dress, against those objections to which it must, at a much earlier period, have appeared to be liable, if the old peripatetic phraseology had been retained. The following passage from Hobbes will show what was the doctrine of his age, and throw light, at the same time, on the opinions which prevailed all over Europe, at no great distance from the era to which our observations apply:

"The philosophy schools through all the universities of Christendom, grounded upon certain texts of Aristotle, teach that for the cause of vision, the thing seen sendeth forth on every side, a visible species, a visible show, apparition, or aspect, or a being seen; the receiving whereof into the eye, is seeing. And for the cause of hearing, that the thing heard sendeth forth an audible species, that is, an audible aspect, or audible being seen; which entering at the ear, maketh hearing. Nay, for the cause of understanding, also, they say the thing understood sendeth forth an intelligible species, that is, an intelligible being seen; which coming into the understanding, maketh us understand.—I not this," he continues, " as disapproving of the use of universities; but because I am to speak hereafter of their office in a commonwealth, I must let you see, on all occasions, by the way, what things should be amended in them, amongst which the frequency of insignificant speech is one.'

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The philosophy of mind cultivated in Scotland, since the time of Dr. Reid, may be characterized by describing it as directly opposed to the idealism of Berkeley and Hume. In this part of. the kingdom, the opinions of Locke in regard to perception have likewise undergone a thorough reformation, though no work, avowedly on the subject, has been allowed to take place of his celebrated "Essay on the Human Understanding." The only system of metaphysics, or, more properly, perhaps, of intellectual physiology, which has, since the epoch alluded to, attracted any attention in England, is that which was brought forward by Hartley, Priestley, and Darwin; and which undertakes to explain all

the phenomena of mind on the principle of nervous vibrations and the association of ideas. But the doctrines of these writers have not acquired any degree of popularity. The tendency which they manifested towards the conclusions of materialism, excited against them, in the first instance, a well-founded suspicion and the extravagance with which their leading speculations were afterwards defended, and pressed upon the acceptance of the learned world, left no room for doubt as to the unphilosophical nature of the views whence they sprang, and the pernicious effects which they could hardly fail to produce.

The system of Dr. Reid has been very ably illustrated by Mr. Stewart, in a variety of publications. Without implicitly adopting all the opinions of his master, he maintains, with much talent, the soundness of his general principles, and particularly those which respect perception and the origin of our ideas. Dr. Brown, to the consideration of whose works we have at length arrived, followed in the same track; using, perhaps, greater freedom in his strictures on the Glasgow philosopher, and modifying more extensively the conclusions to which his reasoning has been found to lead. Unfortunately, for the credit of metaphysics, the one half of every new book is employed in correcting the errors contained in the publication which came out immediately before it; and, what is still much worse, in order to be original it is only necessary to give a slight change to the meaning of a word. Á whole system may be erected on the most trifling addition to the import of the most common term. On this ground, we find some discrepancies raised, in relation to the philosophical opinions of the three authors now named; and in regard to one or two points of considerable importance, Dr. Brown has chosen to espouse the cause of Hume, in preference to the less accurate deductions of his celebrated antagonist.

Of these points, the most interesting, as well as the most difficult, is the doctrine which turns on the relation of Cause and Effect. Hume's essay on that intricate question is well known to every reader of metaphysics; and no one requires to be told, that the sceptical notions which he contrived to introduce into the examination of our ideas respecting that relation, created a very general prejudice against such inquiries altogether, as being either beyond the reach of human intellect, or totally unconnected with any legitimate system of mental philosophy. It occurs to us, however, that the peculiar difficulty which that writer encountered, and the scepticism which he founded upon it, have not been accurately traced to their source. Hume does not deny, that we have the idea of power as applied to causation. He admits that it finds a place in every mind, from the rank of a

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