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LECTURE XXVIII.

ON DR REID'S SUPPOSED PROOF OF A MATERIAL WORLD-ON VISION AND ANALYSIS OF THE FEELINGS ASCRIBED TO IT.

IN my Lecture of yesterday, Gentlemen, we were engaged in considering the grounds of Dr Reid's claim to the honour of detecting and exposing the fallacy of the hypothesis of ideas as images, or things, in the mind, distinct from the mind itself,-a claim which, though made by one who has many other indubitable titles to our respect and gratitude, we found, in this particular instance, to be inadmissible.

It appeared, on an examination of the original works of the eminent philosophers who preceded him for more than a century, and even of the common elementary treatises of the schools, that, though after the Peripatetic hypothesis of species had been universally or generally abandoned, the language of that hypothesis continued to subsist metaphorically, as it continues with equal force at this moment,-it was only metaphorically that it did thus continue; and that when Dr Reid, therefore, conceived,-in proving ideas not to be self-existing things, separate and distinct from the percipient mind itself,—that he was confuting what every body believed, he merely assumed as real what was intended as metaphorical, and overthrew opinions which the authors, to whom he ascribes them, would themselves have been equally eager to overthrow. But there is yet another point, connected with the theory of perception, on which he is believed to have made an important addition to our metaphysical knowledge. I allude to his supposed proof of the existence of a material world. In this, too, we shall find, that he has truly added nothing to our former knowledge; that he has left us, in short, our belief as originally felt by us, but has not supplied us with the slightest evidence in

addition to the force of that original belief itself, nor given any additional strength to that very belief, which before was confessedly irresistible.

The confutation of the scepticism on this subject, it is evident, may be attempted in two ways, by shewing the arguments urged by the sceptic to be logically false; or by opposing to them the belief itself, as of evidence either directly intuitive, or the result, at least, of other intuitions, and early and universal associations and inferences, so irresistible after the first acquisitions of infancy, as to have then all the force of intuition itself. As long as Dr Read confines himself to the latter of these pleas, he proceeds on safe ground; but his footing is not so firm when he assails the mere logic of the sceptic,-for the sceptical argument, as a mere play of reasoning, admits of no reply. It is vain for him to say, that the scepticism proceeding, as he thinks, on the belief of ideas in the mind, as the direct objects of perception, must fall with these ideas; for, though the scepticism may be consistent with the belief of ideas as separate existences in the mind, it does not depend, in the slightest degree, on their existence or non-existence. We have only to change the term ideas into the synonymous phrase affections or states of the mind, and the scepticism, if not stronger, is at least in strength exactly what it was before. In the one case the sceptic will say, that we are sensible of ideas only, not of external objects, which may have no resemblance to our ideas; in the other case, that perception is but a state of the mind as much as any of our other feelings, and that we are conscious only of this, and other states or affections of our mind, which have variously succeeded each other, and not of external objects, which themselves can be no parts of that train of mental consciousness. Whatever weight there may be in the former of these sceptical theories, exists, I may say, even with greater force, because with greater simplicity, in the second; and the task, therefore, of proving by logic,-if logical proof were requisite for our belief,-the existence of a material world, would remain as laborious as before, after the fullest confutation of the system, which might suppose perception to be carried on by the medium of little images of bodies in the mind.

So far, indeed, would the confutation of this hypothesis as to perception, even if Dr Reid had truly overthrown it,-be from

lessening the force of the scepticism as to the existence of matter, that, of two sceptics, one believing every thing with respect to ideas which Dr Reid supposed himself to have confuted, and the other believing ideas to be mere states of his mind, there can be no question, that the former would be the more easy to be overcome, since his belief would already involve the existence of SOMETHING separate from the mind; while the other might maintain, that all of which he was conscious, was the mere series of affections of his own mind, and that beyond this consciousness he could know nothing.

Against the argument of one, who founds his very argument on his consciousness merely, and professes to have no knowledge either of little images, or of any thing else beyond his consciousness, it would be as idle to urge, that ideas are not little images in the mind, as it would have been for a Cartesian to attempt to confute the Newtonian system of attraction, by a denial of the Ptolemaic spheres.

All that remains, then, to supply the place of logical demonstration, which would be needless where the belief is as strong as that of demonstration itself, is the paramount force of this universal and irresistible belief; and there is no fear that this can be weakened by any argument, or be less felt by him who denies it, than by him who asserts it. We are conscious, indeed, only of the feelings that are the momentary states of our own mind; but some of these it is absolutely impossible for us not to ascribe to causes that are external, and independent of us; and the belief of a system of external things, is one of these very states of the mind, which itself forms, and will ever form, a part of the train of our consciousness. This Mr Hume himself, the great sceptic whom Dr Reid opposes, admits as readily as Dr Reid himself:"A Copernican or Ptolemaic, who supports each his different system of astronomy, may hope to produce a conviction, which will remain constant and durable, with his audience. A Stoic or Epicurean displays principles, which may not only be durable, but which have an effect on conduct and behaviour. But a Pyrrhonian cannot expect, that his philosophy will have any constant influence on the mind: or, if it had, that its influence would be beneficial to society. On the contrary, he must acknowledge, if he will acknowledge any thing, that all human life must perish,

were his principles universally and steadily to prevail. All discourse, all action, would immediately cease; and men remain in a total lethargy, till the necessities of nature, unsatisfied, put an end to their miserable existence. It is true, so fatal an event is very little to be dreaded. Nature is always too strong for principle; and, though a Pyrrhonian may throw himself, or others, into a momentary amazement and confusion by his profound reasonings, the first and most trivial event in life will put to flight all his doubts and scruples, and leave him the same, in every point of action and speculation, with the philosophers of every other sect, or with those who never concerned themselves in any philosophical researches. When he awakes from his dream, he will be the first to join in the laugh against himself."* In what respect does this differ from the language of Dr Reid himself, when he says, that "the belief of a material world is older, and of more authority, than any principles of philosophy. It declines the tribunal of reason, and laughs at all the artillery of the logician." Surely, if it decline the tribunal of reason, it is not by reasoning that it is to be supported,even though the reasoner should have the great talents which Dr Reid unquestionably possessed.

The sceptic, and the orthodox philosopher of Dr Reid's school, thus come precisely to the same conclusion. The creed of each, on this point, is composed of two propositions, and of the same two propositions; the first of which is, that the existence of a system of things, such as we understand when we speak of an external world, cannot be proved by argument; and the second, that the belief of it is of a force, which is paramount to that of argument, and absolutely irresistible. The difference, and the only difference is, that, in asserting the same two propositions, the sceptic pronounces the first in a loud tone of voice, and the second in a whisper,-while his supposed antagonist passes rapidly over the first, and dwells on the second, with a tone of confidence. The negation in the one case, and the affirmation in the other case, are, however, precisely the same. To him, indeed, who considers the tone only, and not the meaning, there may seem to be a real strife of sentiment; but, if we neglect the tone, which is of no consequence, and attend to the meaning only of what is Essays Inquiry concerning Human Understanding, Sect. xii. Part 2. + Inquiry into the Human Mind, &c. Chap. v. Sect. 7.

affirmed and denied by both, we shall not be able to discover even the slightest discrepancy. There is no argument of mere reasoning that can prove the existence of an external world; it is absolutely impossible for us not to believe in the existence of an external world. We may call these two propositions, then, a summary of the doctrine of Reid, or of the doctrine of Hume, as we please; for it is truly the common and equal doctrine of the two.

Though we have thus seen reason to deny to Dr Reid the merit commonly ascribed to him, on the points which we have been considering, relative to the theory of perception, I trust you will not on that account, be insensible to the merits which he truly possessed. He knows little, indeed, of the human mind, who does not know, how compatible many errors and misconceptions are with the brighest and most active energies of intellect. On this "Isthmus of a middle State," of which Pope speaks, man, though not "reasoning but to err," is yet subject to occasional error, even in his proudest reasonings. With all his wisdom, he is still but "darkly wise ;" and with all the grandeur of his being, but" rudely great."

VISION.

Our inquiry into the nature of the sensations of touch,—or at least of those sensations, which are truly, and of others which are commonly, though, I think, falsely, ascribed to this organ, has led us into speculations, in the course of which I have been obliged to anticipate many remarks, that more peculiarly belong to the sense which still remains to be considered by us,-the sense of sight, that to which we owe so much of our most valuable information, with respect to nature, and so many of those pleasures, which the bounty of Him, who, has formed us to be happy, as well as to be wise, has so graciously intermingled, with all the primary means of our instruction.

The anticipations, into which I have been led, were necessary for throwing light on the subjects before considered, particularly on the complex feelings ascribed to touch,-the knowledge of which feelings, however, was still more necessary, for understanding fully the complex perceptions of this sense. It is thus