surface to which the forefinger was applied, and which it covered, becomes, and from this time henceforward continues, to be our true eye. Thus, by a very singular process, do we find ourselves, as it were, within our own eye—a procedure which is rescued from absurdity by this consideration, that our eye itself—our tangible eye, is also found within the primary eye, as we may call it, which latter eye falling away when the experience of touch commences, the man and the universe which surrounds him start forth into their true place as external to the seer, and the new secondary eye, revealed by touch, becoming localized, shrinks into its true proportions, now very limited when tactually compared with the objects which fall under its inspection. And all this magical creation—all our knowledge that objects are out of the eye, and that the size of this organ bears an infinitely small proportion to the real magnitude of objects—all this is the work of the touch, and of the touch alone. [1]
Perhaps 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 coextensive 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 not cover, perhaps, the hundred millionth part of its surface. Thus are the judgments and conclusions of the eye corrected and refuted by the experience of 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 large 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 alone is presented to the vision.
By looking through a pair of spectacles, any one may convince himself of the impossibility of our seeing the real and tangible magnitude of things—or of our seeing anything which exceeds the expansion of the retina. A lofty tower, you will say, exceeds the expansion of the retina, certainly a tangible, a suggested tower, does so: but does a visible, a seen tower, ever do so? Make the experiment, good reader, and you will find that it never does. Look, then, at this tower from a small distance, through a pair of spectacles, which form a sort of projected retina, not much, if at all, larger than your real retina. At first sight you will probably say that it looks about a hundred feet high, and, at any rate, that you see it to be infinitely larger than your own eye. But look again, attending in some degree to the size of your spectacle glasses, and you shall see that it does not stretch across one half, or perhaps one fourth, of their diameter. And if a fairy pencil, as Adam Smith supposes, were to come between your eye and the glass, the picture sketched by it thereon, answering in the exactest conformity to the dimensions of the tower you see, would be an image, probably not the third of an inch high, or the hundredth part of an inch broad. This is certainly not what you seem to see, but this is certainly what you do see. These are the dimensions into which your lofty tower has shrunk. Now is this tower, seen to be one-third of an inch high, and very much smaller than the retina, represented by the spectacles—is this tower another tower, seen to be a hundred feet high, and infinitely larger than the retina, and existing out of the mind in rerum natura? or is not the latter tower merely suggested by the former ideal one, in consequence of the great disparity which touch, and touch alone, has proved to exist between the thing seeing and the thing seen? Unquestionably the latter view of the matter is the true one; seen objects are always ideal, and always remain ideal; they have no existence in rerum natura. They merely suggest other objects of a real, or at least of a tangible kind,
- ↑ It may, perhaps, be thought that all this information might be acquired by the simple act of closing our eyelids. But here the tactual sensations are so faint that we might be doubtful whether the veil was drawn over our eye or over the face of things. Our limits prevent us from stating other objections to which this explanation is exposed.
