“Wherefore, distance being only a line and not of itself perceivable, if an object were conveyed to the eye by one single ray only, there were no other means of judging of its distance but by some of those hinted before. Therefore when we estimate the distance of nigh objects, either we take the help of both eyes; or else we consider the pupil of one eye as having breadth, and receiving a parcel of rays from each radiating point. And, according to the various inclinations of the rays from one point on the various parts of the pupil, we make our estimate of the distance of the object. And therefore (as is said before), by one single eye we can only judge of the distance of such objects to whose distance the breadth of the pupil has a sensible proportion.... For, it is observed before (prop. 29, sec. 2, see also _Gregorii Opt. Promot._ prop. 29) that for viewing objects remote and nigh, there are requisite various conformations of the eye—the rays from nigh objects that fall on the eye diverging more than those from more remote objects.” (_Treatise of Dioptrics_, Part I. prop. 31.) ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ All this helps to shew the state of science regarding vision about the time Berkeley’s _Essay_ appeared, especially among those with whose works he was familiar(278). I shall next refer to illustrations of the change which the _Essay_ produced. The _New Theory_ has occasioned some interesting criticism since its appearance in 1709. At first it drew little attention. For twenty years after its publication the allusions to it were few. The account of Cheselden’s experiment upon one born blind, published in 1728, in the _Philosophical Transactions_, which seemed to bring the Theory to the test of scientific experiment, recalled attention to Berkeley’s reasonings. The state of religious thought about the same time confirmed the tendency to discuss a doctrine which represented human vision as interpretation of a natural yet divine language, thus suggesting Omnipresent Mind. Occasional discussions of the _New Theory_ may be found in the _Gentleman’s Magazine_, from 1732 till Berkeley’s death in 1753. Some criticisms may also be found in Smith’s _Optics_, published in 1738. Essential parts of Berkeley’s analysis are explained by Voltaire, in his _Élémens de la Philosophie de Newton_. The following from that work is here given on its own account, and also as a prominent recognition of the new doctrine in France, within thirty years from its first promulgation:—