learn it by experience, with the joint co-operation of touch and sight.

As the facts connected with this experiment for cataract are exceedingly curious, both in a metaphysical point of view and as connected with the theory of vision, we shall state them more at length. This young man thought scarlet the most beautiful of all colours, and the first time he saw black it gave him very great uneasiness; and when he saw a negro woman he was quite shocked. At first he knew not the shape of anything, nor could he distinguish one object from another by their figure or magnitude. He was very much surprised that those things which he liked best did not appear the most agreeable to his eyes; for he calculated that those persons would appear most beautiful whom he loved the most. About two months after he had been couched, pictures appeared to him as solid bodies, but before he considered them only as partycoloured planes, or surfaces diversified with a variety of paints. Being shown his father's picture in a locket at his mother's watch, and told what it was, he acknowledged a likeness, but was vastly surprised, asking how it could be that a large face could be expressed in so little room. The room he was in, he said, he knew to be but part of the house; yet he could not conceive that the whole house could look bigger. A year after his first seeing, being carried to Epsom Downs, and observing a large prospect, he was exceedingly delighted with it, and called it a new kind of seeing. Only having been couched in one eye at first, after the second

one was operated on, all objects appeared to him. much larger by this eye, than by the other; but he had not, Mr. Cheselden says, double vision, that he was ever able to discover.*

Voltaire was among the first in France to make the Bishop's theory public. In his "Elements of the Newtonian Philosophy," the poet and philosopher makes the following remarks. "It is absolutely necessary to admit, that distance, magnitude, and figure, are not, properly speaking, visible objects; that is, they are not the proper and immediate objects of sight. The proper and immediate objects of vision are light and colours; all the rest we learn in the course of time by experience alone. We learn to see, just as we learn to speak and to read. The only difference is, that the act of seeing is more easy, inasmuch as nature is our tutor in this instance."

The soundness of this theory of Berkeley's has recently been called in question by Mr. Bailey, in a work entitled "A Review of Berkeley's Theory of Vision." The whole question is gone into with great care and minuteness. Mr. Bailey has pointedly directed attention to the phenomena of consciousness, and attempts to show that there is no foundation for the Bishop's opinion from this source. He has analysed our perceptions of magnitude and figure, and maintains that our notions of these things do not bear out Berkeley's theory. The visual perceptions manifested by the animal

* See Smith's Optics, book 1.

creation, by infants, and by persons operated on for blindness, are all opposed to the ideas of Berkeley.

Mr. Bailey makes a preliminary distinction on the question at issue, which it is necessary to keep in view, when sitting in judgment on his opinions. He says, there is one statement, that sight alone is unable to determine that visible things are external, or at any distance whatever from the eye; and the other point is, that sight, though possessed of the power of estimating that objects are placed at some distance from the organ of vision, has not the power of perceiving and estimating the relative distances between two or more things. He says, "Whether objects are seen to be external or at some distance, is one question altogether distinct from the inquiry, whether objects are seen by the unassisted vision to be at different distances from the percipient." And then the author adds, "yet Berkeley uniformly assumes them to be the same; or, at least, takes it for granted that they are to be determined by the same arguments."

We cannot, for want of space, enter into the controversy; we shall merely quote a concluding paragraph from the work of Mr. Bailey, and refer the reader to the treatise itself for further information on this curious and interesting subject. "This general reception of it (Berkeley's theory) is undoubtedly a proof of the great ingenuity with which it is developed and maintained, and yet, a close examination will scarcely fail to convince any

* A Review of Berkeley's Theory, p. 16.

one, that the Essay towards a New Theory of Vision, is rather a clever mustering of plausible arguments in support of a favourite notion, by a mind delighting in its own subtility, than a masterly exposition of the subject in hand, or a skilful arrangement of a train of ideas in their due logical order and dependence. It has little method, and abounds in repetition for want of it, while the author scarcely seems at all times sufficiently master of the impalpable and shadowy notions which he has called up, to escape confusion and perplexity."*

We cannot leave this part of our subject, without making a reference to an able review of Mr. Bailey's work, in one of the most popular and spirited periodicals of the day; namely, Blackwood's Magazine. The reader will find Berkeley's Theory supported with great ingenuity. We shall just quote a sentence or two, which may, perhaps, throw some light on the matter:-" The following consideration may help the reader to understand how the sight becomes instructed by the touch. Our natural visual judgment undoubtedly is, as we have said, that the eye and the landscape which it sees are precisely co-extensive with each other; and the natural conclusion must be, that whatever surface is sufficient to cover the one, must be sufficient to cover the other also. But is this found to be the case? By no means. You lay your finger on your eye, and it completely covers it. You then lay the same finger on the landscape, and it does

Review, p. 238.

† For June, 1842.

not cover, perhaps, the hundred millionth part of its surface. Thus are the judgments and conclusions of the eye corrected and refuted by the finger, until at length the eye actually believes that it sees things to be larger than itself—a total mistake, however, on its part, as Berkeley was the first to show; for the object which it seems to see as greatly larger than itself, is only suggested by another object which is always smaller than itself. The small visible object suggests the thought of a larger tangible object, and the latter it is which chiefly occupies the mind; but still it is never seen; it is merely suggested by the other object which is presented to the vision."*

The opinions entertained by Bishop Berkeley on the nature of abstract ideas and abstract terms, are important. He strikes at the root of all realism. We shall quote a few passages from his works on this subject.

"In order to prepare the mind of the reader for the easier conceiving what follows, it is proper to premise somewhat, by way of introduction, concerning the nature and abuse of language. But the unravelling this matter leads me in some measure to anticipate my design, by taking notice of what seems to have had a chief part in rendering speculation intricate and perplexed, and to have occasioned innumerable errors and difficulties in almost all parts of knowledge. And that is the opinion that the mind hath a power of framing abstract ideas or