the New Theory of Vision,’ which was published not long since, wherein it is shown that distance, or outness, is neither immediately of itself perceived by sight, nor yet apprehended, or judged of, by lines and angles or anything that hath any necessary connection with it; but that it is only suggested to our thoughts by certain visible ideas and sensations attending vision, which, in their own nature, have no manner of similitude or relation either with distance, or with things placed at a distance; but by a connection taught us by experience, they come to signify and suggest them to us, after the same manner that words of any language suggest the ideas they are made to stand for; insomuch that a man born blind and afterwards made to see, would not, at first sight, think the things he saw to be without his mind or at any distance from him.”

The key-note of the Essay to which Berkeley refers in this passage is to be found in an italicized paragraph of section 127:—­

“The extensions; figures, and motions perceived by sight are specifically distinct from the ideas of touch called by the same names; nor is there any such thing as an idea, or kind of idea, common to both senses.”

It will be observed that this proposition expressly declares that extension, figure, and motion, and consequently distance, are immediately perceived by sight as well as by touch; but that visual distance, extension, figure, and motion, are totally different in quality from the ideas of the same name obtained through the sense of touch.  And other passages leave no doubt that such was Berkeley’s meaning.  Thus in the 112th section of the same Essay, he carefully defines the two kinds of distance, one visual, the other tangible:—­

“By the distance between any two points nothing more is meant than the number of intermediate points.  If the given points are visible, the distance between them is marked out by the number of interjacent visible points; if they are tangible, the distance between, them is a line consisting of tangible points.”

Again, there are two sorts of magnitude or extension:—­

“It has been shown that there are two sorts of objects apprehended by sight, each whereof has its distinct magnitude or extension:  the one properly tangible, i.e. to be perceived and measured by touch, and not immediately falling under the sense of seeing; the other properly and immediately visible, by mediation of which the former is brought into view.”—­Sec. 55.

But how are we to reconcile these passages with others which will be perfectly familiar to every reader of the “New Theory of Vision “?  As, for example:—­

    “It is, I think, agreed by all, that distance of itself, and
    immediately, cannot be seen.”—­Sec. 2.

    “Space or distance, we have shown, is no otherwise the object
    of sight than of hearing.”—­Sec. 130.