ultimate view, that I have in the "Essay on Consciousness" offered arguments, which I humbly trust are conclusive, that the brain cannot for a moment be supposed either to perform the functions of mind, or even any thing like those functions which Dr. Hartley has ingeniously attributed to it, as mental operations. I have indeed, in the same Essay, offered a very different conjecture; and whatever is its complexion, I hope it is at least satisfactory against the supposition of a cerebral percipient.-I confess farther, though it is great presumption, that I am even willing to hope its general principle may be found the natural barrier against the doctrine of materialism: a hope which absorbs my care as to any particular faults it may appear to have, in the eyes of those who may honor it with their criticism.

I consider the evidences of a distinct mind to be so various, and satisfactory, that they must remove every doubt if we but advance to examine them in the only way that sound sense, or philosophy, can allow; instead of shrinking for fear that truth may conduct us to the enemy's post. But one thing is certain, that if we do thus shrink, say what else we can, the doctrine of materialism will advance and any other doctrine, which does but shut our eyes upon the danger, will not prevent its progress.

That men will at once abandon opinions in which they have long been confirmed, is not in ordinary to be expected; but they must yield when they themselves refute them: and let it not here be forgot, that besides the proofs now about to be brought, the foregoing sections have pointed out so very conspicuous a counter evidence in the doctrine of total non-resemblance as admits no relief, but amounts to a complete suicide; and which, without any other evidence, would decide the question. I, of course, think no evidence against Dr. Reid's theory can be thought more strong than his own but such is the magnitude of the subject, that number, and variety, of evidences must still be deeply interesting. Hence we proceed.

PROP. II. We perceive superficial figure strictly with the sensation that betrays it; and to it we habitually add, a wrong belief that it is external.

Perhaps the most important question in philosophy is,-how we get the knowledge of extension and figure, simply considered. It is sufficiently known, that what has been called the common theory of perception, which, under varieties, was generally maintained from the early ages down to that of Bishop Berkeley, supposed that the figures we perceive by sense, are some sort of intermediate beings, existing and operating between the mind and external bodies. This scheme, therefore, left the existence of external bodies at best but conjectural, and open to objection. It is also known that Berkeley having, in his own conception, confounded perceived figure with the sensation that betrays it to us, therefore deemed all figures mere ideal things; and thus insisted on the non-existence of an extended world.-The philosopher Hume, equally confounding forms with feelings, went on, with a characteristic acuteness, and independence in thinking, to show, that the principles maintained by both Berkeley and himself, lead to the annihilation of minds, as well as of bodies.-Thus, through all recorded time, mankind have had no better philosophical ground to rest upon, than what is built upon doubt.

To Dr. Reid the world stands indebted, for having attacked the fabric of Berkeleian errors, in asserting the difference between feelings and the forms they betray to us.-In so doing, he exploded the only ground upon which the dismal conclusions of both Berkeley and Hume are built, and restored to us our wonted state of doubt but it is freely confessed, that he has left the existence of the external world, as it always was, open to the cavils of scepticism. It will, doubtless, appear very presumptuous to say, that more might have been done; but at all risks I am compelled to think, that he turned off at the next step to a mighty truth; which, also, I suppose nothing could have hid from him, except that previous bias which prevented his discerning, that perception of xtension is a primary fact.

Two vast differences exist, between the theory of perception advanced by Dr. Reid, and that which I labor to set forth.-First, That he held perception of figure, to be perception of an external separate thing.-Secondly, That he held external things to be perceived by instinct upon sensation;—and so denied one grand province of the exercise of intellect.- -It is now time to state the process, itself, of perception, after the manner apprehended by each party; and this perhaps may be, by some, better understood from a particular instance, than in a general proposition.

First-according to Dr. Reid-When we perceive (let us say) a green gooseberry, its "external quality, color," occasions a sensation, or "the appearance of this color in the mind," without extension or figure of this appearance: and this is followed by “instinctive" perception, of—both figure—and its externality.

Here I merely notice the inconsistency, in a teacher of non-resemblance, (after calling "color a quality of body,") in making sensations of colour "appearances in the mind, of this quality of body." But as, to balance this, he makes appearances non-extended;-and without one " resembling feature" of the quality of which they are" apparitions;" who can clear such a tissue of contradiction? Unextended appearances, (which, also, are "apparitions" of extended qualities) recoil with such force, upon those who adopt them, as to furnish a signal example to the ablest, who dispute nature's fact of the extension of color in the mind.-See Reid's Inquiry," chap. 6.

I have been very desirous to state, as far as possible, the words which convey the substance of this Hypothesis; which I could not explain by offering any one passage of the author, so as to exhibit the statements which his whole doctrine expressly contains, and the consequences which it involves.-It will be rigidly scrutinised, and it is impossible I should intend to strain the import.

Next--On my part,-We no more know external things by sense and instinct, than mathematics by sense and instinct.

When I perceive a green gooseberry, I suffer a sensation of green, extended over a plane circle, it being a necessary substratum without which this sensation of green could not exist in my mind But I have learned, from what happens to blind men on receiving

their sight, that this appearance of a green circle could never, of itself, afford me any conception of an external cause or thing. Nevertheless it is true, that repeated contemplations of changes, have led, and have habituated me, to refer daily sensations to external causes; so that, now, whenever I perceive such green figure, I add to it, the conception of externality, solidity, &c.: and so (without feeling any complexness of fact) make out what is called the perception of a gooseberry. But in this case, what is felt, is no evidence whether the fact of perception of figure, is a different process from the added conception of externality. It is from other facts, only, that we are to learn it. In proof of this, when an illiterate back-gammon player throws sixes, he conceives sixes as instantaneously as he perceives mere figure itself, and would stare to be told of an exercise of intellect: but, it is certain that, after the sensation with figure, he has conceived the number of twice six,-and super-added the conception of their equality. It therefore is not present feeling, but analysis, that is to decide this grand question; and it is decided, for the process is analyzed, and proved complex.

It depends wholly on the exercise of intellect, upon collateral and remembered circumstances, whether any sensation shall be followed by a conception of an external thing like that perceived. -A sick man in the dark suffers figures, which he well judges to have no external cause like what is perceived; he therefore perceives nothing without him: but a man in a delirium judges otherwise; for he connects such figures with an erroneous conception of their externality. A real circle is perceived from revolutions of an ignited stick; but we then conceive no external circle.

Again, Suppose we confidently perceive two soldiers on guard, but upon approaching them it proves, that one only is a real man, and the other but a reflection, from a mirror placed to deceive.Here it is evident that, at first, we properly perceived no more of one figure than of the other, that is to say only superficial figure; and in this we neither were nor could be deceived:, but one of the things in question is a real external body, and the other, (agreeably with Dr. Reid himself,) is "only the appearance in the mind, of the colors" of a man; it having no external existence. It becomes clear, that to both perceived figures we have

added a conception of externality, and trine dimension; which conception was produced by reflecting reason, that led us to expect two real men. Had it been the result of gifted instinct, Nature's law would not have perceived true in one case, and false in the other.

All external perception is notoriously a game of hazard, or result of reasoning upon circumstances:-While, certainly, no appearance of figure leads a sane man to perceive any external thing, unless he has collateral evidence which helps him to judge, that the figure has an external cause-which he knows is not always the case.

It is very important to remark here, that my great present aim is to show, that heretofore there has obtained, a denial of some existing facts-a confusion of others-and a consequent erroneous conclusion, in some one branch of every theory here brought into consideration:-And, that it is necessary these be discerned, and acknowledged, before the Philosophy of the Mind can advance. Many of those who hold with Locke and Berkeley (as I do) that we perceive figure with sensation, yet err, in supposing, also, that we perceive external things with sensation. And here it is surprising that even Dr. Reid has so far countenanced this party, as to deny intellect its vast province of perceiving the external world.

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Those, on the other hand, who assert against Reid (as I do) that external perception is from reasoning; unfortunately add a related error, in supposing that perception of figure is from reasoning and thus side with Dr. Reid, that all perceived figures are the external things of the world. Yet here the inconsistency of these two schools is manifest; for, while such theorists make figure itself perceived by reason,-Dr. Reid ascribes it to instinct, which last makes it quite a different process of the mind.

It becomes of the highest consequence to notice, and unravel, this confusion; and to show,-That nature has permitted us to discover (and philosophy must therefore adopt) the perception of figure alone,—different from,-independent of,—and often ex-` isting without,-any perception, or conception, of any external thing.