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6. There is another way mentioned by the 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 (according to Berkeley) are the common and current accounts” given by mathematicians of our perceiving near distances by sight. He then proceeds to show, that they are unsatisfactory; and that it is necessary, for the solution of this problem, to avail ourselves of principles borrowed from a higher philosphy: After which, he explains, in detail, his own theory concerning the ideas (sensations) which, by experience, become signs of distance ; * or (to use his own phraseology) “ by which distance is suggested t to the mind." The result of the whole is, that, “a man horn blind, being made to see, would not at first have any idea of distance by sight. The

* For assisting persons unaccustomed to metaphysical studies to enter into the spirit and scope of Berkeley's Theory, the best illustration I know of is furnished by the phenomena of the Phantasmagoria. It is sufficient to hint at this application of these phenomena, to those who know any thing of the subject.

† The word suggest is much used by Berkeley in this appropriate and technical sense, not only in his Theory of Vision, but in his Principles of Human Knowledge, and in his Minute Philosopher. It expresses, indeed, the cardinal principle on which his Theory of Vision hinges; and is now so incorporated with some of our best metaphsical speculations, that one cannot easily conceive how the use of it was so long dispensed with. Locke (in the passage quoted in the Note, p. 107) uses the word excite for the same purpose; but it seems to imply an hypothesis concerning the mechanism of the mind, and by no means expresses the fact in question with the same force and precision.

It is remarkable, that Dr. Reid should have thought it incumbent on him to apolo. gize for introducing into philosophy a word so familiar to every person conversant with Berkeley's works. “I beg leave to make use of the word suggestion, because I know not one more proper to express a power of the mind, which seems entirely to have escaped the notice of philosophers, and to which we owe many of our simple notions which are neither impressions nor ideas, as well as many original principles of belief. I shall endeavour to explain, by an example, what I understand by this word. We all know that a certain kind of sound suggests immediately to the mind a coach passing in the street; and not only produces the imagination, but the belief, that a coach is passing. Yet there is no comparing of ideas, no perception of agreements or disagreements to produce this belief; nor is there the least similitude between the sound we hear, and the coach we imagine and believe to be passing.”

So far Dr. Reid's use of the word coincides exactly with that of Berkeley; but the former will be found to annex to it a meaning more extensive than the latter, by employing it to comprehend not only those intimations which are the result of experience and habit; but another class of intimations (quite overlooked by Berkeley,) those which result from the original frame of the human mind. (See Reid's Inquiry, Chap. ii. sec. 7.)

sun and stars, the remotest objects, as well as the nearest, would all seem to be in his Eye, or rather in his Mind."*

From this quotation it appears, that, before Berkeley's time, philosophers had advanced greatly beyond the point at which Aristotle stopped, and towards which Condillac, in his first publication, made a retrograde movement. Of this progress some of the chief steps may be traced as early as the twelfth century, in the Optics of Alhazen; † and they may be perceived still more clearly and distinctly in various optical writers since the revival of letters; particularly in the Optica Promota of James Gregory. I Father Malebranche went still farther, and even anticipated some of the metaphysical reasonings of Berkeley concerning the means by which experience enables us to judge of the distances of near objects. In proof of this, it is sufficient to mention the explanation he gives of the manner, in which a comparison of the perceptions of sight and of touch teaches us gradually to estimate by the eye, the distances of all those objects which are within reach of our hands, or of which we are accustomed to measure the distance, by walking over the intermediate ground.

In rendering this justice to earlier writers, I have no wish to detract from the originality of Berkeley. With the single exception, indeed, of the passage in Malebranche which I have just referred to, and which it is more than probable was unknown to Berkeley when his theory first occurred to him, Ş I have ascribed to his predecessors nothing more than what he has himself explicitly acknowledged to belong to them. All that I wished to do was, fo supply some links in the historical chain, which he has omitted.

The influence which this justly celebrated work has had, not only in perfecting the theory of optics, but in illustrating the astonishing effects of early habit on the mental phenomena in general, will sufficiently account to my intelligent readers for the length to wbich the foregoing observations upon it have extended.

* I request the attention of my readers to this last sentence, as I have little doubt that the fact here stated gave rise to the theory which Berkeley afterwards adopted, concerning the nonexistence of the material world. It is not, indeed, surprising that a conclusion, so very curious with respect to the objects of sight, should have been, in the first ardor of discovery, too hastily extended to those qualities also which are the appropriate objects of touch.

† Alhazen, Lib. ii. NN. 10, 12, 39. | See the end of Prop. 28.

$ Berkeley's Theory was published when he was only twenty-five; an age when it can scarcely be supposed that his metaphysical reading had been very extensive. * See Philosophical Essuys.

Next in point of importance to Berkeley's New Theory of Vision, which I regard as by far the most solid basis of his philosophical fame, may be ranked his speculations concerning the Objects of General Terms, and his celebrated argument against the existence of the Material World. On both of these questions I have elsewhere explained my own ideas so fully, that it would be quite superfluous for me to resume the consideration of them here.* In neither instance are his reasonings so entirely original as has been commonly supposed. In the former, they coincide in substance, although with immense improvements in the form, with those of the scholastic Nominalists, as revived and modified by Hobbes and Leibnitz. In the latter instance, they amount to little more than an ingenious and elegant developement of some principles of Malebranche, pushed to certain paradoxical but obvious consequences, of which Malebranche, though unwilling to avow them, appears to have been fully aware. These consequences, too, had been previously pointed out by Mr. Norris, a very learned divine of the Church of England, whose name has unaccountably failed in obtaining that distinction, to which his acuteness as a logician, and his boldness as a theorist, justly entitled him.t

† Another very acute metaphysician of the same church (Arthur Collier, author of a Demonstration of the Non-existence and Impossibility of an External World) has met with still greater injustice. His name is not to be found in any of our Biographical Dictionaries. In point of date, his publication is some years posterior to that of Norris, and therefore it does not possess the same claim to originality: but it is far superior to it in logical closeness and precision, and is not obscured to the same degree with the mystical theology which Norris (after the example of Malebranche) connected with the scheme of Idealism. Indeed, when compared with the writings of Berkeley himself, it yields to them less in force of argument, than in composition and variety of illustration. The title of Collier's book is, Clavis Universalis, or a New Inquiry after Truth, being a Demonstration, &c. &c. By Arthur Collier, Rector of Langford Magna, near Sarum. (Lond. printed for Robert Gosling, at the Mitre and Crown, against St. Dunstan's Church, Fleet Street, 1713.) The motto prefixed by Collier to his work is from Malebranche, and is strongly characteristical both of the English and French Inquirer after Truth. “ Vulgi assensus et approbatio circa materiam difficilem est certum argumentum falsitatis istius opinionis cui assentitur.” (Maleb. de Inquir. Verit. Lib. iii. p. 194.) See Note (Oo.) * I allude here chiefly to Alciphron, or the Minute Philosopher ; for as to the dialogues between Hylas and Philonous, they aspire to no higher merit than that of the common dialogues between A. and B.; being merely a compendious way of stating and of obviating the principal objections which the author anticipated to his opinions.

The great object of Berkeley in maintaining his system of idealism, it may be proper to remark in passing, was to cut up by the roots, the scheme of materialism. “ Matter," he tells us himself, “ being once expelled out of nature, drags with it so many sceptical and impious notions. **** Without it, your Epicureans, Hobbists, and the like, have not even the shadow of a pretence, but become the most cheap and easy triumph in the world.”

Not satisfied with addressing these abstract speculations to the learned, Berkeley conceived them to be of such moment to human happiness, that he resolved 'to, bring them, if possible, within the reach of a wider circle of readers, by throwing them into the more popular and amusing form of dialogues.* The skill with which he has executed this very difficult and unpromising task cannot be too much admired. The characters of his speakers are strongly marked and happily contrasted; the illustrations exhibit a singular combination of logical subtility and of poetical invention; and the style, while it everywhere abounds with the rich, yet sober colorings of the author's fancy, is perhaps superior, in point of purity and of grammatical correctness, to any English composition of an earlier date.t

The impression produced in England by Berkeley's Idealism was not so great as might have been expected : but the novelty of his paradoxes attracted very powerfully the attention of a set of young men who were then prosecuting their studies at Edinburgh, and who formed themselves into a Society for the express purpose of soliciting from the author an explanation of some parts of his theory which seemed to them obscurely or equivocally expressed. To this correspondence the amiable and ex

Dr. Warton, after bestowing high praise on the Minute Philosopher, excepts from his encomium “ those passages in the fourth dialogue, where the auihor has introduced his fanciful and whimsical opinions about vision.”-(Essay on the Writings and Genius of Pope. Vol. II. p. 264.)—If I were called on to point out the most ingenious and original part of the whole work, it would be the argument contained in the passages here so contemptuously alluded to, by this learned and (on all ques. tions of taste) most respectable critic.

cellent prelate appears to have given every encouragement; and I have been told by the best authority, that he was accustomed to say, that his reasonings had been nowhere better understood than by this club of young Scotsmen.* The ingenious Dr. Wallace, author of the Discourse on the Numbers of Mankind, was one of the leading members; and with him were associated several other individuals, whose names are now well known and honorably distinguished in the learned world. Mr. Hume's Treatise of Humon Nature, which was published in 1739, affords sufficient evidence of the deep impression which Berkeley's writings had left upon his Nind; and to this juvenile essay of Mr. Hume's may be traced the origin of the most important metaphysical works which Scotland has since produced.

It is not, however, my intention to prosecute farther, at present, the history of Scotish philosophy. The subject may be more conveniently, and I hope advantageously resumed, after a slight review of the speculations of some English and French writers, who, while they professed a general acquiescence in the doctrines of Locke, have attempted to modify his fundamental principles in a manner totally inconsistent with the views of their master. The remarks which I mean to offer on the modern French school will afford me, at the same time, a convenient opportunity of introducing some strictures on the metaphysical systems which have of late prevailed in other parts of the Continent.

SECTION V.

Haitleian School The English writers to whom I have alluded in the last paragraph, I shall distinguish by the title of Dr. Hartley's School; for although I by no means consider this person as the first author of any of the theories commonly ascribed to him (the seeds of all of them having

* The authority I here allude to is that of my old friend and preceptor, Dr. John Stevenson, who was himself a member of the Rankenian Club, and who was accustomed for many years to mention this fact in his Academical Prelections. VOL. VI.

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