Blackwood's Magazine/Volume 53/Issue 332/Mr. Bailey's Reply to an Article in Blackwood's Magazine

by James Frederick Ferrier

MR. BAILEY'S REPLY TO AN ARTICLE IN BLACKWOOD'S MAGAZINE.

We have just been favoured with a pamphlet from Mr Bailey, entitled "A Letter to a Philosopher, in Reply to some Recent Attempts to Vindicate Berkeley's Theory of Vision, and in further Elucidation of its Unsoundness." Our article on Mr Bailey's review of Berkeley's theory, which appeared in Blackwood's Magazine of June 1842, was one of these attempts. Had the author merely attacked or controverted our animadversions on his book, we should probably have left the question to its fate, and not have reverted to a subject, the discussion of which, even in the first instance, may have been deemed out of place in a journal not expressly philosophical. There is, in general, little to be gained by protracting such controversies. But, as Mr Bailey accuses us, in the present instance, of having misrepresented his views, we must be allowed to exculpate ourselves from the charge of having dealt, even with unintentional unfairness, towards one whose opinions, however much we may dissent from them, are certainly entitled to high respect and a candid examination, as the convictions of an able and zealous enquirer after truth.

In our strictures on Mr Bailey's work, we remarked, that he had represented Berkeley as holding that the eye is not directly and originally cognizant of the outness of objects in relation to each other, or of what we would call their reciprocal outness; in other words, we stated, that, according to Mr Bailey, Berkeley must be regarded as denying to the eye the original intuition of space, either in length, breadth, or solid depth. It was, however, only in reference to one of his arguments, and to one particular division of his subject, that we laid this representation to his charge. Throughout the other parts of his discussion, we by no means intended to say that such was the view he took of the Berkeleian theory. Nor are we aware of having made any statement to that effect. If we did, we now take the opportunity of remarking, that we restrict our allegation, as we behave we formerly restricted it, to the single argument and distinction just mentioned, and hereafter to be explained.

In his reply, Mr Bailey disavows the impeachment in toto. He declares that he never imputed to Berkeley the doctrine, that the eye is not directly percipient of space in the two dimensions of length and breadth. "The perception of this kind of distance," says he, " never formed the subject of controversy with any one . . . That we see extension in two dimensions is admitted by all."—( Letter, p. 10.) If it can be shown that the doctrine which is here stated to be admitted by all philosophers, is yet expressly controverted by the two metaphysicians whom Mr Bailey appears to have studied most assiduously, it is, at any rate, possible that he may have overlooked, in his own writings, the expression of an opinion which has escaped his penetration in theirs. To convince himself then, how much he is mistaken in supposing that the visual intuition of longitudinal and lateral extension is admitted by all philosophers, he has but to turn to the works of Dr Brown and the elder Mill. In arguing that we have no immediate perception of visible figure, Dr Brown not only virtually, but expressly, asserts that the sight has no perception of extension in any of its dimensions. Not to multiply quotations, the following will, no doubt, be received as sufficient:—"They (i.e. philosophers) have—I think without sufficient reason—universally supposed that the superficial extension of length and breadth becomes known to us by sight originally."^[1] Dr Brown then proceeds to argue, with what success we are not at present considering, that our knowledge of extension and figure is derived from another source than the sense of sight.

Mr James Mill, an author whom Mr Bailey frequently quotes with approbation, and in confirmation of his own views, is equally explicit. He maintains, in the plainest terms, that the eye has no intuition of space, or of the reciprocal outness of visible objects. "Philosophy," says he," has ascertained that we derive nothing from the eye whatever but sensations of colour—that the idea of extension [he means in its three dimensions] is derived from sensations not in the eye, but in the muscular part of our frame."^[2] Thus, contrary to what Mr Bailey affirms, these two philosophers limit the office of vision to the perception of mere colour or difference of colour, denying to the eye the original perception of extension in any dimension whatever. In their estimation, the intuition of space is no more involved in our perception of different colours than it is involved in our perception of different smells or different sounds. Dr Brown's doctrine, in which Mr Mill seems to concur, is, that the perception of superficial extension no more results from a certain expanse of the optic nerve being affected by a variety of colours than it results from a certain expanse of the olfactory nerve being affected by a variety of odours.^[3] So much for Mr Bailey's assertion, that all philosophers admit the perception of extension in two dimensions.

But, of course, our main business is with the expression of his own opinion. In rebutting our charge, he maintains that "the visibility of angular distance (that is of extension laterally) is assumed, by implication, as part of Berkeley's doctrine, in almost every chapter of my book."—( Letter, p. 13.) That word almost is a provident saving clause; for we undertake to show that not only is the very reverse assumed, by implication, as part of Berkeley's doctrine, in the single chapter to which we confined our remarks, but that, in another part of his work, it is expressly avowed as the only alternative by which, in the author's opinion, Berkeley's consistency can be preserved.

At the outset of his enquiry, Mr Bailey divides his discussion into two branches: first, Whether objects are originally seen to be external, or at any distance at all from the sight; and, secondly, Supposing it admitted that they are seen to be external, or at some distance from the sight, whether they are all seen in the same plane, or equally near. It was to the former of these questions that we exclusively confined our remarks;^[4] and it was in reference to it, and to an important argument evolved by Mr Bailey in the course of its discussion, that we charged him with fathering on Berkeley the doctrine which he now disavows as his interpretation of the bishop's opinion. He further disputes the relevancy of the question about our perception of lateral extension, and maintains that distance in a direction from the percipient, or what we should call protensive distance, is the only matter in dispute; and that it is a misconception of the scope of Berkeley's essay to imagine otherwise. The relevancy of the question shall be disposed of afterwards. In the mean time, the question at issue is, Can the allegation which we have laid to Mr Bailey's charge be proved to be the fact, or not?

In discussing the first of the two questions, it was quite possible for Mr Bailey to have represented Berkeley as holding, that visible objects, though not seen to be external to the sight, were yet seen to be out of each other, or laterally extended within the organism or the mind. But Mr Bailey makes no such representation of the theory, and the whole argument which pervades the chapter in which the first question is discussed, is founded on the negation of any such extension. All visible extension, he tells us, must, in his opinion, be either plane or solid. Now he will scarcely maintain that he regarded Berkeley as holding that we perceive solid extension within the organism of the eye. Neither does he admit that, according to Berkeley, and in reference to this first question, plane extension is perceived within the organism of the eye. For when he proceeds to the discussion of the second of the two questions, he remarks that "we must, at this stage of the argument, consider the theory under examination, as representing that we see all things originally in the same plane,"^[5] obviously implying that he had not as yet considered the theory as representing that we see things originally in the same plane: in other words, plainly admitting that, in his treatment of the first question, he had not regarded the theory as representing that we see things originally under the category of extension at all.

But if any more direct evidence on this point were wanted, it is to be found in the section of his work which treats of "the perception of figure." In the chapter in which he discusses the first of the two questions, he constantly speaks of Berkeley's theory as representing that "our visual sensations, or what we ultimately term visible objects, are originally mere internal feelings." The expression mere internal feelings, however, is ambiguous; for, as we have said, it might still imply that Mr Bailey viewed the theory as representing that there was an extension, or reciprocal outness of objects within the retina. But this doubt is entirely removed by a passage in the section alluded to, which proves that, in Mr Bailey's estimation, these mere internal feelings not only involve no such extension, but that there would be an inconsistency in supposing they did. In this section he brings forward Berkeley's assertion, "that neither solid nor plane figures are immediate objects of sight." He then quotes a passage in which the bishop begs the reader not to stickle too much "about this or that phrase, or manner of expression, but candidly to collect his meaning from the whole sum and tenour of his discourse." And then Mr Bailey goes on to say, "endeavouring, in the spirit here recommended, to collect the author's meaning when he affirms that the figures we see are neither plane nor solid, it appears to me to be a part or consequence of his doctrine already examined, which asserts that visible objects are only internal feelings."^[6] We can now be at no loss to understand what Mr Bailey means, and conceives Berkeley to mean, by the expression "mere internal feelings." He evidently means feelings in which no kind of extension whatever is involved: for, in the next page, he informs us that all visual extension, or extended figure, "must be apprehended as either plane or solid, and that it is impossible even to conceive it otherwise." Consequently, if the figures we see are, as Berkeley says, apprehended neither as plane nor as solid, Mr Bailey, entertaining the notions he does on the subject of extension, must regard him as holding that they cannot be apprehended as extended at all—and accordingly such is the express representation he gives of the theory in the passage just quoted, where he says that "the doctrine of Berkeley, which affirms that the figures we see are neither plane nor solid, (that is, are extended in no direction, according to Mr Bailey's ideas of extension,) appears to him to be a part of the doctrine which asserts that visible objects are only internal feelings." Now if that be not teaching, in the plainest terms, that, according to Berkeley, no species of extension is implied in the internal feelings of vision, we know not what language means, and any one thought may be identical with its very opposite.

Here we might let the subject drop, having, as we conceive, said quite enough to prove the truth of our allegation that, in reference to the first question discussed, in which our original visual sensations are represented by Berkeley to be mere internal feelings, Mr Bailey understood and stated those feelings to signify sensations in which no perception of extension whatever was involved. However, as Mr Bailey further remarks that, "although Berkeley's doctrine about visible figures being neither plane nor solid, is thus consistent with his assertion that they are internal feelings, it is in itself contradictory,"^[7] we shall contribute a few remarks to show that while, on the one hand, the negation of extension is not required to vindicate the consistency of Berkeley's assertion, that visible objects are internal feelings, neither, on the other hand, is there any contradiction in Berkeley's holding that objects are not seen either as planes or as solids, and are yet apprehended as extended. Mr Bailey alleges that we are "far more successful in involving ourselves in subtle speculations of our own, than in faithfully guiding our readers through the theories of other philosophers. " Perhaps in the present case we shall be able to thread a labyrinth where our reviewer has lost his clue, and, in spite of the apparent contradiction by which Mr Bailey has been gravelled, we shall, perhaps, be more successful than he in "collecting Berkeley's meaning from the whole sum and tenour of his discourse."

First, with regard to the contradiction charged upon the bishop. When we open our eyes, what do we behold? We behold points—minima visibilia—out of one another. Do we see these points to be in the same plane? Certainly not. If they are in the same plane we learn this from a very different experience from that of sight. Again, do we see these points to be not in the same plane? Certainly not. If the points are not in the same plane we learn this, too, from a very different experience than that of sight. All that we see is that the points are out of one another; and this simply implies the perception of extension, without implying the perception either of plane or of solid extension. Thus by the observation of a very obvious fact, which, however, Mr Bailey has overlooked, is Berkeley's assertion that visible objects are apprehended as extended, and yet not apprehended either as planes or solids, relieved from every appearance of contradiction.

It must, however, be admitted that Mr Bailey has much to justify him in his opinion that extension must be apprehended either as plane or as solid. None of Berkeley's followers, we believe, have ever dreamt of conceiving it otherwise, and finding in their master's work the negation of solid extension specially insisted on, they leapt to the conclusion that the bishop admitted the original perception of plane extension. But Berkeley makes no such admission. He places the perception of plane extension on precisely the same footing with that of solid extension. "We see planes," says he, "in the same way that we see solids."^[8] And the wisdom of the averment is obvious; for the affirmation of plane extension involves the negation of solid extension, but this negation involves the conception (visually derived) of solid extension; but the admission of that conception, so derived, would be fatal to the Berkeleian theory. Therefore its author wisely avoids the danger by holding, that in vision we have merely the perception of what the Germans would call the Auseinanderseyn, that is, the asunderness, of things—a perception which implies no judgment as to whether the things are secerned in plane or in protensive space.

With regard to the supposition that, in order to preserve Berkeley's consistency, it was necessary for him to teach that our visual sensations, (colours namely,) being internal feelings, could involve the perception neither of plane nor of solid extension, that is to say, of no extension at all, according to Mr Bailey's ideas, we shall merely remark, that there appears to us to be no inconsistency in holding, as Berkeley does, that these colours, though originally internal to the sight, are nevertheless perceived. as extended among themselves.

We shall now say a few words on the relevancy of the question, for Mr Bailey denies that this question, concerning the reciprocal outness of visible objects, ought to form any element in the controversy. We shall show, however, that one of his most important arguments depends entirely on the view that may be taken of this question; and that while the argument alluded to would be utterly fatal to Berkeley's theory, if the perception of reciprocal outness were denied, it is perfectly harmless if the perception in question be admitted.

Mr Baileys fundamental and reiterated objection to Berkeley's theory is, that it requires us to hold that conceptions or past impressions, derived from one sense, (the touch,) are not merely recalled when another sense (the sight) executes its functions, but are themselves absolutely converted into the present intuitions of that other sense. In his own words, (Review, p. 69,) the theory is said to require "a transmutation of the conceptions derived from touch into the perceptions of sight." " According to Berkeley, (says he, Review, p. 22,) an internal feeling (i.e. a visual sensation) and an external sensation (i.e. a tactual sensation) having been experienced at the same time: the internal feeling, when it afterwards occurs, not only suggests the idea, but, by doing so, suggests the idea, or, if I may use the figure, infuses the perception of its own externality. Berkeley thus attributes to suggestion an effect contrary to its nature, which, as in the case of language, is simply to revive in our conception what has been previously perceived by the sense."

Now, this objection would be altogether insurmountable if it were true, or if it were a part of Berkeley's doctrine, that the sight has no original intuition of space, or of the reciprocal outness of its objects—in other words, of colours out of colours; for it being admitted that the sight has ultimately such a perception, it would be incumbent on the Berkeleian to show how conceptions derived from another sense, or how perceptions belonging to another sense, could be converted into that perception. We agree with Mr Bailey, in thinking that no process of association could effect this conversion; that if we did not originally see colours to be out of each other and the points of the same colour to be out of each other, we could never so see them; and that his argument, when thus based on the negation of all original visual extension, and on the supposition that the touch is the sole organ of every species of externality, would remain invulnerable.

But, with the admission of the visual intuition of space, the objection vanishes, and the argument is shorn of all its strength. This admission relieves the theory from the necessity of maintaining, that conceptions derived from touch are transmuted into the perceptions of sight. It attributes to the sight all that ever truly belongs to it, namely, the perception of colours out of one another; it provides the visual intuitions with an externality of their own—and the theory never demands that they should acquire any other; and it leaves to these visual intuitions the office of merely suggesting to the mind tactual impressions, with which they have been invariably associated in place. We say, in place; and it will be found that there is no contradiction in our saying so, when we shall have shown that it is the touch, and not the sight, which establishes a protensive interval between the organ and the sensations of vision.

Visible extension, then, or the perception of colours external to colours, being admitted, Mr Bailey's argument, if he still adheres to it, must be presented to us in this form. He must maintain that the theory requires that the objects of touch should not only be suggested by the visual objects with which they have been associated, but that they should actually be seen. And then he must maintain that no power of association can enable us to see an object which can only be touched—a position which, certainly, no one will controvert. The simple answer to all which, is, that we never do see tangible objects—that the theory never requires we should, and that no power of association is necessary to account for a phenomenon which never takes place.

We cannot help thinking, that not a little of the misconception on this subject which prevails in the writings of Mr Bailey, and, we may add, of many other philosophers, originates in the supposition that we identify vision with the eye in the mere act of seeing, and in their taking it for granted that sight of itself informs us that we possess such an organ as the eye. Of course, if we suppose that we know instinctively, or intuitively, from the mere act of seeing, that the eye is the organ of vision, that it forms a part of the body we behold, and is located in the head, it requires no conjurer to prove that we must have an instinctive, or intuitive, knowledge of visible things as larger than that organ, and, consequently, as external to it. In this case, no process of association is necessary to account for our knowledge of the distance of objects. That knowledge must be directly given in the very function and exercise of vision, as every one will admit, without going to the expense of an octavo volume to have it proved.

But we hold that no truth in mental philosophy is more incontestable than this, that the sight originally, and of itself, furnishes us with no knowledge of the eye, as we now know that organ to exist. It does not inform us that we have an eye at all. And here we may hazard an observation, which, simple as it is, appears to us to be new, and not unimportant in aiding us to unravel the mysteries of sensation; which observation is, that, in no case whatever, does any sense inform us of the existence of its appropriate organ, or of the relation which subsists between that organ and its objects, but that the interposition of some other sense^[9] is invariably required to give us this information. This truth, which we believe holds good with regard to all the senses, is most strikingly exemplified in the case of vision, as we shall now endeavour to illustrate.

Let us begin by supposing that man is a mere "power of seeing." Under this supposition, we must hold that the periphery of vision is one and the same with the periphery of visible space; and the two peripheries being identical, of course whatever objects lie within the sphere of the one must lie within the sphere of the other also. Perhaps, strictly speaking, it is wrong to say that these objects are apprehended as internal to the sight; for the conception of internality implies the conception of externality, and neither of these conceptions can, as yet. be realized. But it is obvious what he expression internal means; and it is unobjectionable, when understood to signify that the Seeing Power, the Seeing Act, and the Seen Things, co-exist in a synthesis in which there is no interval or discrimination. For, suppose that we know instinctively that the seen things occupy a locality separate from the sight. But that implies that we instinctively know that the sight occupies a locality separate from them. But such a supposition is a falling back upon the notion just reprobated, that the mere act of seeing can indicate its own organ, or can localise the visual phenomena in the eye—a position which, we presume, no philosopher will be hardy enough to maintain, when called upon to do so, broadly and unequivocally. The conclusion, therefore, is irresistible, that, in mere vision, the sight and its objects cling together in a union or synthesis, which no function of that sense, and no knowledge imparted to us by it, (and, according to the supposition, we have, as yet, no other knowledge,) can enable us to discriminate or dissolve. Where the seeing is, there is the thing seen, and where the thing seen is, there is the seeing of it.

But man is not a mere seeing animal. He has other senses besides: He has, for example, the sense of touch, and one of the most important offices which this sense performs, is to break up the identity or cohesion which subsists between sight and its objects. And how? We answer, by teaching us to associate vision in general, or the abstract condition regulating our visual impressions, with the presence of the small tangible body we call the eye, and vision in particular, or the individual sensations of vision, (i.e. colours,) with the presence of immeasurably larger bodies revealed to us by touch, and tangibly external to the tangible eye. Sight, as we have said, does not inform us that its sensations are situated in the eye: it does not inform us that we have an eye at all. Neither does touch inform us that our visual sensations are located in the eye. It does not lead us to associate with the eye any of the visual phenomena or operations in the first instance. If it did, it would (firstly) either be impossible for it afterwards to induce us to associate them with the presence of tangible bodies distant and different from the eye: or, (secondly), such an association would merely give birth to the abstract knowledge or conclusion, that these bodies were in one place, while the sensations suggesting them were felt to be associated with something in another place; colour would not be seen—as it is—incarnated with body: or, (thirdly), we should be compelled to postulate for the eye, as many philosophers have done, in our opinion, most unwarrantably, "a faculty of projection"^[10] by which it might dissolve the association between itself and its sensations, throwing off the latter in the form of colours over the surface of things, and reversing the old Epicurean doctrine that perception is kept up by the transit to the sensorium of the ghosts or simulacra of things,

"Quæ, quasi membranæ, summo de corpore rerum
Dereptæ, volitant ultro citroque per auras."^[11]

It is difficult to say whether the hypothesis of "cast-off films" is more absurd when we make the films come from things to us as spectral effluxes, or go from us to them in the semblance of colours.

But according to the present view no such incomprehensible faculty, no such crude and untenable hypothesis, is required. Before the touch has informed us that we have an eye, before it has led us to associate any thing visual with the eye, it has already taught us to associate in place the sensations of vision (colours) with the presence of tangible objects which are not the eye. Therefore, when the touch discovers the eye, and induces us to associate vision in some way with it, it cannot be the particular sensations of vision called colours which it leads us to associate with that organ; for these have been already associated with something very different. If it be not colours, then what is it that the touch compels us to associate with the eye? We answer that it is the abstract condition of impressions as the general law on which all seeing depends, but as quite distinct from the particular visual sensations apprehended in virtue of the observance of that law.

Nor is it at all difficult to understand how this general condition comes to be associated with the eye, and how the particular visual sensations come to be associated with something distant from the eye: and further, how this association of the condition with one thing, and of the sensations with another thing, (an association established by the touch and not by the sight,) dissolves the primary synthesis of seeing and colours. It is to be observed that there are two stages in the process by which this secernment is brought about—First, the stage in which the visual phenomena are associated with things different from the organ of vision, the very existence of which is as yet unknown. Let us suppose, then, the function of sight to be in operation. We behold a visible object—a particular colour. Let the touch now come into play. We feel a tangible object—say a book. Now from the mere fact of the visible and the tangible object being seen and felt together, we could not associate them in place; for it is quite possible that the tangible object may admit of being withdrawn, and yet the visible object remain: and if so, no association of the two in place can be established. But this is a point that can only be determined by experience; and what says that wise instructor? We withdraw the tangible object. The visible object, too, disappears: it leaves its place. We replace the tangible object—the visible object reappears in statu quo. There is no occasion to vary the experiment. If we find that the visible object invariably leaves its place when the tangible object leaves its, and that the one invariably comes back when the other returns, we have brought forward quite enough to establish an inevitable association in place between the two. The two places are henceforth regarded, not as two, but as one and the same.

By the aid of the touch, then, we have associated the visual phenomena with things which are not the organ of vision; and well it is for us that we have done so betimes, and before we were aware of the eye's existence. Had the eye been indicated to us in the mere act of seeing; had we become apprised of its existence before we had associated our visual sensations with the tangible objects constituting the material universe, the probability, nay the certainty, is that we would have associated them with this eye, and that then it would have been as impossible for us to break up the association between colours and the organ, as it now is for us to dissolve the union between colours and material things. In which case we should have remained blind, or as bad as blind; brightness would have been in the eye when it ought to have been in the sun; greenness would have been in the retina when it ought to have been in the grass. A most wise provision of nature it certainly is, by which our visual sensations are disposed of in the right way before we obtain any knowledge of the eye. And most wisely has nature seconded her own scheme by obscuring all the sources from which that knowledge might be derived. The light eyelids—the effortless muscular apparatus performing its ministrations so gently as to be almost unfelt—the tactual sensations so imperceptible when the eye is left to its own motions, so keen when it is invaded by an exploring finger, and so anxious to avoid all contact by which the existence of the organ might be betrayed. All these are so many means adopted by nature to keep back from the infant seer all knowledge of his own eye—a knowledge which, if developed prematurely, would have perverted the functions, if not rendered nugatory the very existence of the organ.

But, secondly, we have to consider the stage of the process in which vision is in some way associated with an object which is not any of the things with which the visual sensations are connected. It is clear that the process is not completed—that our task, which is to dissolve the primary synthesis of vision and its phenomena, is but half executed, unless such an object be found. For though we have associated the visual sensations (colours) with something different from themselves, still vision clings to them without a hair's-breadth of interval, and pursues them whithersoever they go. As far, then, as we have yet gone, it cannot be said that our vision is felt or known to be distanced from the fixed stars even by the diameter of a grain of sand. The synthesis of sight and colour is not yet discriminated. How, then, is the interval interposed? We answer, by the discovery of a tangible object in a different place from any of the tangible objects associated with colour; and then by associating, in some way or other, the operations of vision with this object. Such an object is discovered in the eye. Now, as has frequently been said, we cannot associate colours or the visual sensations with this eye; for these have been already disposed of otherwise. What, then, do we associate with it—and how? We find, upon experiment, that our apprehension of the various visual sensations depends on the presence and particular location of this small tangible body. We find that the whole array of visual phenomena disappear when it is tactually covered, that they reappear when it is reopened, and so forth. Thus we come in some way to associate vision with it—not as colour, however, not as visual sensation. We regard the organ and its dispositions merely as a general condition regulating the apprehension of the visual sensations, and no more.

Thus, by attending to the two associations that occur,—the association (in place) of visual sensations with tangible bodies that are not the eye; and the association (in place) of vision with a small tangible body that is the eye—the eye regarded as the condition on which the apprehension of these sensations depends; by attending to these, we can understand how a protensive interval comes to be recognised between the organ and its objects. By means of the touch, we have associated the sensations of vision with tangible bodies in one place, and the apprehension of these sensations with a tangible body in another place. It is, therefore, impossible for the sight to dissolve these associations, and bring the sensations out of the one place where they are felt, into the other place where the condition of their apprehension resides. The sight is, therefore, compelled to leave the sensations where they are, and the apprehension of them where it is; and to recognize the two as sundered from each other—the sensations as separated from the organ, which they truly are. Thus it is that we would explain the origin of the perception of distance by the eye; believing firmly that the sight would never have discerned this distance without the mediation of the touch.

Rightly to understand the foregoing reasoning—indeed to advance a single step in the true philosophy of sensation—we must divest ourselves of the prejudice instilled into us by a false physiology, that what we call our organism, or, in plain words, our body, is necessarily the seat of our sensations. That all our sensations come to be associated in some way with this body, and that some of them even come to be associated with it in place, is undeniable; but so far is it from being true, that they are all essentially implicated or incorporated with it, and cannot exist at a distance from it, that we have a direct proof to the contrary in our sensations of vision; and until the physiologist can prove (what has never yet been proven) an à priori necessity that our sensations must be where our bodies are, and an à priori absurdity in the contrary supposition, he must excuse us for resolutely standing by the fact as we find it.

This is a view which admits of much discussion, and we would gladly expatiate upon the subject, did time and space permit; but we must content ourselves with winding up the present observations with the accompanying diagram, which we think explains our view beyond the possibility of a mistake.

Let A be the original synthesis, or indiscrimination of vision and its sensations—of light and colours. Let á be the visual sensations locally associated by means of the touch with the tangible bodies C before vision is in. any way associated with B—before, indeed, we have any knowledge of the existence of B. Then let a, the general condition on which the sensations, after a time, are found to depend, and in virtue of which they are apprehended, be locally associated with B—the eye discovered by means of the touch—and we have before us what we cannot help regarding as a complete rationale of the whole phenomena and mysteries of vision. Now, the great difference between this view of the subject and the views of it that have been taken by every other philosopher, consists in this, that whereas their explanations invariably implicated the visual sensations á with B from the very first, thereby rendering it either impossible for them to be afterwards associated with C, or possible only in virtue of some very extravagant hypothesis—our explanation, on the contrary, proceeding on a simple observation of the facts, and never implicating the sensations á with B at all, but associating them with C à primordiis, merely leaving to be associated with B, a, a certain general condition that must be complied with, in order that the sensations á may be apprehended,—in this way, we say, our explanation contrives to steer clear both of the impossibility and the hypothesis.

We would just add by way of postscript to this article—which, perhaps, ought itself to have been only a postscript—that with regard to Mr Bailey's allegation of our having plagiarised one of his arguments, merely turning the coat of it outside in, we can assure him that he is labouring under a mistake. In our former paper, we remarked that we could not see things to be out of the sight, because we could not see the sight itself. Mr Bailey alleges, that this argument is borrowed from him, being a mere reversal of bis reasoning, that we cannot see things to be in the sight, because we cannot see both the sight and the things.—That our argument might very naturally have been suggested by his, we admit. But it was not so. We had either overlooked the passage in his book, or it was clean out of our mind when we were pondering our own speculations. It did not suggest our argument, either nearly or remotely. Had it done so, we should certainly have noticed it, and should probably have handled both Mr Bailey's reasoning and our own to better purpose, in consequence. If, notwithstanding this disclaimer, he still thinks that appearances are against us, we cannot mend his faith, but can merely repeat, that the fact is as we have stated it.

1. Brown's Lectures, Lecture xxviii.
2. Mill's Analysis, vol. i. p. 73.
3. This reasoning of Dr Brown's is founded upon an assumed analogy between the structure of the optic nerve, and the structure of the olfactory nerves and other sensitive nerves, and is completely disproved by the physiological observations of Treviranus, who has shown that no such analogy exists: that the ends of the nervous fibres in the retina being elevated into distinct separate papillæ, enable us to perceive the extension, and discriminate the position of visible bodies,—while the nerves of the other senses being less delicately defined, are not fitted to furnish us with any such perception, or to aid us in making any such discrimination. See Müller's Physiology, translated by W. Baly, M.D. , vol. ii. pp. 1073, 1074. Although the application of Treviranus's discovery to the refutation of Dr Brown's reasoning is our own, we may remark, in justice to an eminent philosopher, that it was Sir William Hamilton who first directed our attention to the fact as established by that great physiologist.
4. Mr Bailey seems disposed to carp at us for having confined our remarks to this first question, and for not having given a more complete review of his book. But the reason why we cut short our critique is obvious; for if it be proved, as we believe it can, that objects are originally seen at no distance whatever from the sight, it becomes quite superfluous to enquire what appearance they would present if originally seen at some distance from the sight. The way in which we disposed of the first question, however imperfect our treatment of it may have been, necessarily prevented us from entering upon the second; and our review, with all its deficiencies, was thus a complete review of his book, though not a review of his complete book.
5. Review of Berkeley's Theory, p 35.
6. Ibid. p. 136.
7. Review of Berkeley's Theory, p. 137.
8. Essay, § 158.
9. It would not be difficult to show., that as, on the one hand, distance is not involved in the original intuitions of sight, so, on the other hand, proximity is not involved in the original intuitions of touch; but that, while it is the touch which establishes an interval between the organ and the objects of sight, it is the sight which establishes no interval between the organ and the objects of touch. Sight thus pays back every fraction of the debt it has incurred to its brother sense. This is an interesting subject, but we can only glance at it here.
10. We observe that even Müller speaks of the "faculty of projection" as if he sanctioned and adopted the hypothesis.—See Physiology, vol. ii. p. 1167.
11. Lucretius.