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 believe 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."[28] 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."[29] 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.[30] 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;[31] 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?