une raison supérieure, et cette indulgence qui appartient à une bienveillance éclairée."*

* The best Edition of the Works of Hemsterhuis is that Edited in 1826, in 2 vols., Louvain, by M. Sylvain Van de Weyer, now Belgian Envoy Extraordinary at the Court of London.-See Note C. at the End of this Volume.

CHAPTER VII.

BERKELEY AND COLLIER.

BISHOP BERKELEY.

BISHOP Berkeley is one of the most acute and distinguished metaphysicians of whom England can boast. No man ever cultivated philosophy, and published so much that was of a really debatable nature, and yet made so few personal enemies. He was admired and esteemed by all who had the happiness of his acquaintance. Atterbury says of him, "So much understanding, so much knowledge, so much innocence, and so much hu- ` mility, I did not think had been the portion of any but angels, till I saw this gentleman."

Berkeley's metaphysical disquisitions are chiefly contained in his "New Theory of Vision," published in 1709; his "Principles of Human Knowledge," printed in 1710; and the "Dialogues of Hylas and Philonous," which made their appearance a year or two after. These are all works of singular genius, profundity, and merit. They naturally divide his

whole philosophy into three parts; 1st, His theory of vision; 2nd, His opinions on the nature of abstract ideas; and 3rd, His notions on the non-existence of matter. These three divisions constitute the three pillars on which his system rests.

The theory of vision propounded by Berkeley was one of the most brilliant mental discoveries of the eighteenth century. Its principles may be briefly stated in the following observations.

The aim of the author is to make us perceive the immediate and natural appearance of all objects of sight, from those conclusions of the understanding, respecting their figure, magnitude, distance, situation, &c., which we seem to come to by an almost instantaneous perception. Our ordinary notions upon the subject are, that we judge of the figure, distance, situation, &c. of external objects, by the sense of sight alone. But this, the learned Bishop demonstrates, is not the case. The faculty of sight alone will not impart these judgments to us. There must be the operations of another sense joined to that of sight, namely, the sense of touch or feeling. The impression which is made on us by external objects, through the means of sight alone, is, in metaphysical language, termed the original perception; and the impression made on us by the joint operations of sight and touch, is called the acquired perception.

The following remarks, from the Introduction to the Essay on Vision, will make this matter a little more comprehensible to the ordinary reader. The author says, "It is, I think, agreed by all, that

distance, of itself, cannot be seen. For distance being a line directed end-wise to the eye, it projects only one point in the fund of the eye, which point remains invariably the same, whether the distance be longer or shorter.

"I find it also acknowledged, that the estimate we make of the distance of objects considerably remote, is rather an act of judgment grounded on experience, than of sense. For example, when I perceive a great number of intermediate objects, such as houses, fields, rivers, and the like, which I have experienced to take up a considerable space, I thence form a judgment or conclusion that the object I see beyond them is at a great distance. Again, when an object appears faint and small, which, at a near distance, I have experienced to make a vigorous and large appearance, I instantly conclude it to be far off. And this, it is evident, is the result of experience; without which, from the faintness and littleness, I should not have inferred any thing concerning the distance of objects.

"But when an object is placed at so near a distance, as that the interval between the eyes bears any sensible proportion to it, it is the received opinion that the two optic axes, concurring at the object, do there make an angle, by means of which, according as it is greater or less, the object is perceived to be nearer or farther off.

"There is another way mentioned by optic writers, whereby they will have us judge of those distances, in respect of which the breadth of the pupil hath any sensible bigness; and that is, the greater

or less divergency of the rays which, issuing from the visible point, do fall on the pupil; that point being judged nearest, which is seen by most diverging rays, and that remoter, which is seen by less diverging rays."

These statements are made by the Bishop to show what was the current of opinion amongst philosophers as to the nature of vision. But he considers them all unsatisfactory, and states his own theory. This, by a variety of details, he expounds; shews the reader how the ideas of distance, &c. are suggested to the mind; and then establishes the conclusion of his own investigations into this curious and interesting subject by stating, "that a man born blind, being made to see, would not at first have any idea of distance by sight. The sun and stars, the remotest object as well as the nearest, would all seem to be in his eye, or rather in his mind."

This theory of Dr. Berkeley's was, after its publication, fully established by the famous operation which Dr. Cheselden performed on a young man, for cataract in both eyes, who had been blind for many years by the effects of small pox. The result of the experiment was that the man felt a set of entirely novel sensations. He said everything was in his eye at once, and he could not tell the distance of anything. This he had to learn from experience, by the assistance of the faculty of touch. During his blindness he had learned to distinguish the dog from the cat; but when couched, he could not tell the difference between them, and had to