Aristotle"s doctrine of ????? a?s??s?? would go far, if carried out, to modify his doctrine of the simple and innate character of the senses, e.g. sight (cf. _Eth._ II. 1, 4), and would prevent its collision with Berkeley"s _Theory of Vision_."-See also Sir W.
Hamilton, _Reid"s Works_, pp. 828-830.
Dugald Stewart (_Collected Works_, vol. I. p. 341, note) quotes Aristotle"s _Ethics_, II. 1, as evidence that Berkeley"s doctrine, "with respect to the acquired perceptions of sight, was quite unknown to the best metaphysicians of antiquity."
278 A work resembling Berkeley"s in its t.i.tle, but in little else, appeared more than twenty years before the _Essay_-the _Nova Visionis Theoria_ of Dr. Briggs, published in 1685.
279 See _Treatise on the Eye_, vol. II. pp. 299, &c.
280 See Reid"s _Inquiry_, ch. v. ---- 3, 5, 6, 7; ch. vi. -- 24, and _Essays on the Intellectual Powers_, II. ch. 10 and 19.
281 While Sir W. Hamilton (_Lectures on Metaphysics_, lxxviii) acknowledges the scientific validity of Berkeley"s conclusions, as to the way we judge of distances, he complains, in the same lecture, that "the whole question is thrown into doubt by the a.n.a.logy of the lower animals," i.e. by their probable _visual instinct_ of distances; and elsewhere (Reid"s _Works_, p. 137, note) he seems to hesitate about Locke"s Solution of Molyneux"s Problem, at least in its application to Cheselden"s case. Cf. Leibniz, _Nouveaux Essais_, Liv. II. ch. 9, in connexion with this last.
282 An almost solitary exception in Britain to this unusual uniformity on a subtle question in psychology is found in Samuel Bailey"s _Review of Berkeley"s Theory of Vision, designed to show the unsoundness of that celebrated Speculation_, which appeared in 1842.
It was the subject of two interesting rejoinders-a well-weighed criticism, in the _Westminster Review_, by J.S. Mill, since republished in his _Discussions_; and an ingenious Essay by Professor Ferrier, in _Blackwood"s Magazine_, republished in his _Philosophical Remains_. The controversy ended on that occasion with Bailey"s _Letter to a Philosopher in reply to some recent attempts to vindicate Berkeley"s Theory of Vision, and in further elucidation of its unsoundness_, and a reply to it by each of his critics. It was revived in 1864 by Mr. Abbott of Trinity College, Dublin, whose essay on _Sight and Touch_ is "an attempt to disprove the received (or Berkeleian) Theory of Vision."
283 Afterwards (in 1733) Earl of Egmont. Born about 1683, he succeeded to the baronetcy in 1691, and, after sitting for a few years in the Irish House of Commons, was in 1715 created Baron Percival, in the Irish peerage. In 1732 he obtained a charter to colonise the province of Georgia in North America. His name appears in the list of subscribers to Berkeley"s Bermuda Scheme in 1726. He died in 1748. He corresponded frequently with Berkeley from 1709 onwards.
284 Similar terms are applied to the sense of seeing by writers with whom Berkeley was familiar. Thus Locke (_Essay_, II. ix. 9) refers to sight as "the most comprehensive of all our senses." Descartes opens his _Dioptrique_ by designating it as "le plus universal et le plus n.o.ble de nos sens;" and he alludes to it elsewhere (_Princip._ IV. 195) as "le plus subtil de tous les sens." Malebranche begins his a.n.a.lysis of sight (_Recherche_, I. 6) by describing it as "le premier, le plus n.o.ble, et le plus etendu de tous les sens." The high place a.s.signed to this sense by Aristotle has been already alluded to. Its office, as the chief organ through which a conception of the material universe as placed in ambient s.p.a.ce is given to us, is recognised by a mult.i.tude of psychologists and metaphysicians.
285 On Berkeley"s originality in his Theory of Vision see the Editor"s Preface.
286 In the first edition alone this sentence followed:-"In treating of all which, it seems to me, the writers of Optics have proceeded on wrong principles."
287 Sect. 2-51 explain the way in which we learn in seeing to judge of Distance or Outness, and of objects as existing remote from our organism, viz. by their a.s.sociation with what we see, and with certain muscular and other sensations in the eye which accompany vision. Sect. 2 a.s.sumes, as granted, the invisibility of distance in the line of sight. Cf. sect. 11 and 88-_First Dialogue between Hylas and Philonous-Alciphron_, IV. 8-_Theory of Vision Vindicated and Explained_, sect. 62-69.
288 i.e. outness, or distance outward from the point of vision-distance in the line of sight-the third dimension of s.p.a.ce. Visible distance is visible s.p.a.ce or interval between two points (see sect. 112). We can be sensibly percipient of it only when _both_ points are seen.
289 This section is adduced by some of Berkeley"s critics as if it were the evidence discovered by him for his _Theory_, instead of being, as it is, a pa.s.sing reference to the scientific ground of the already acknowledged invisibility of outness, or distance in the line of sight. See, for example, Bailey"s _Review of Berkeley"s Theory of Vision_, pp. 38-43, also his _Theory of Reasoning_, p. 179 and pp. 200-7-Mill"s _Discussions_, vol. II. p. 95-Abbott"s _Sight and Touch_, p. 10, where this sentence is presented as "the sole positive argument advanced by Berkeley." The invisibility of outness is not Berkeley"s discovery, but the way we learn to interpret its visual signs, and what these are.
290 i.e. aerial and linear perspective are acknowledged signs of remote distances. But the question, in this and the thirty-six following sections, concerns the visibility of _near_ distances only-a few yards in front of us. It was "agreed by all" that beyond this limit distances are suggested by our experience of their signs.
291 Cf. this and the four following sections with the quotations in the Editor"s Preface, from Molyneux"s _Treatise of Dioptrics_.
292 In the author"s last edition we have this annotation: "See what Des Cartes and others have written upon the subject."
293 In the first edition this section opens thus: "I have here set down the common current accounts that are given of our perceiving near distances by sight, which, though they are unquestionably received for true by mathematicians, and accordingly made use of by them in determining the apparent places of objects, do nevertheless," &c.
294 Omitted in the author"s last edition.
295 i.e. although immediately invisible, it is mediately seen. Mark, here and elsewhere, the ambiguity of the term _perception_, which now signifies the act of being conscious of sensuous phenomena, and again the act of inferring phenomena of which we are at the time insentient; while it is also applied to the object perceived instead of to the percipient act; and sometimes to imagination, and the higher acts of intelligence.
296 "Some men"-"mathematicians," in first edition.
297 i.e. the _mediate_ perception.
298 "any man"-"all the mathematicians in the world," in first edition.
299 Omitted in the author"s last edition.
300 Omitted in the author"s last edition.
301 Sect. 3, 9.
302 Observe the first introduction by Berkeley of the term _suggestion_, used by him to express a leading factor in his account of the visible world, and again in his more comprehensive account of our knowledge of the material universe in the _Principles_. It had been employed occasionally, among others, by Hobbes and Locke. There are three ways in which the objects we have an immediate perception of in sight may be supposed to conduct us to what we do not immediately perceive: (1) Instinct, or what Reid calls "_original suggestion_"
(_Inquiry_, ch. VI. sect. 20-24); (2) Custom; (3) Reasoning from accepted premisses. Berkeley"s "suggestion" corresponds to the second. (Cf. _Theory of Vision Vindicated_, sect. 42.)
303 In the _Theory of Vision Vindicated_, sect. 66, it is added that this "sensation" belongs properly to the sense of touch. Cf. also sect. 145 of this _Essay_.
304 Here "natural"="necessary": elsewhere=divinely arbitrary connexion.
305 That our _mediate_ vision of outness and of objects as thus external, is due to media which have a contingent or arbitrary, instead of a necessary, connexion with the distances which they enable us to see, or of which they are the signs, is a cardinal part of his argument.
306 Sect. 2.
307 Here, as generally in the _Essay_, the appeal is to our inward experience, not to phenomena observed by our senses in the organism.
308 See sect. 35 for the difference between confused and faint vision.
Cf. sect. 32-38 with this section. Also _Theory of Vision Vindicated_, sect. 68.
309 See sect. 6.
310 These sections presuppose previous contiguity as an a.s.sociative law of mental phenomena.
311 See Reid"s _Inquiry_, ch. vi. sect. 22.
312 Sect. 16-27.-For the signs of remote distances, see sect. 3.
313 These are muscular sensations felt in the organ, and degrees of confusion in a visible idea. Berkeley"s "arbitrary" signs of distance, near and remote, are either (_a_) invisible states of the visual organ, or (_b_) visible appearances.
314 In Molyneux"s _Treatise of Dioptrics_, Pt. I. prop. 31, sect. 9, Barrow"s difficulty is stated. Cf. sect. 40 below.
315 Christopher Scheiner, a German astronomer, and opponent of the Copernican system, born 1575, died 1650.
316 Andrea Tacquet, a mathematician, born at Antwerp in 1611, and referred to by Molyneux as "the ingenious Jesuit." He published a number of scientific treatises, most of which appeared after his death, in a collected form, at Antwerp in 1669.
317 In what follows Berkeley tries to explain by his visual theory seeming contradictions which puzzled the mathematicians.
318 This is offered as a verification of the theory that near distances are suggested, according to the order of nature, by non-resembling visual signs, contingently connected with real distance.
319 Cf. sect. 78; also _New Theory of Vision Vindicated_, sect. 31.
320 Berkeley here pa.s.ses from his proof of visual "suggestion" of all outward distances-i.e. intervals between extremes in the line of sight-by means of arbitrary signs, and considers the nature of visible externality. See note in Hamilton"s _Reid_, p. 177, on the distinction between perception of the external world and perception of distance through the eye.
321 See Descartes, _Dioptrique_, VI-Malebranche, _Recherche_, Liv. I.
ch. 9, 3-Reid"s _Inquiry_, VI. 11.
322 Berkeley here begins to found, on the experienced connexion between extension and colour, and between visible and tangible extension, a proof that _outness_ is invisible. From Aristotle onwards it has been a.s.sumed that colour is the only phenomenon of which we are immediately percipient in seeing. Visible extension, visible figure, and visible motion are accordingly taken to be dependent on the sensation of colour.
323 In connexion with this and the next ill.u.s.tration, Berkeley seems to argue that we are not only unable to see distance in the line of sight, but also that we do not see a distant object in its _real visible_ magnitude. But elsewhere he affirms that only _tangible_ magnitude is ent.i.tled to be called _real_. Cf. sect. 55, 59, 61.