A THEORY OF SIGHT.*
Ma GOBLET has ventured upon a task requiring peculiar qualifications. He has attempted to present in a popular form a subject of some metaphysical complexity, and possessing no great prima facie attraction. For such a work a certain degree of imaginative colouring is highly desirable. To this there is no pretension. A systematic plan, however, accurate, language, and clear argument, are absolutely necessary. The first of these is attempted, but not faithfully observed. The language often justifies an immediate construction wholly at variance with the author's views, while in the argument are sometimes such gaps as to render pursuit a matter of hypothesis and laborious sagacity. Occasionally one part of the book contradicts another, and want of uniformity of interest and value in the matter is a conspicuous defect. If literary compositions were classed according to specific gravity, this would fall under the head of gaseous. It is less of that solid consistency which its name suggests than a nebulous mass with occasional nuclei of more aggregated matter, but insufficient, we fear, to secure its permanence in this lower atmosphere. On the other hand, there is an evident love of truth and an intelligent interest in the subject.
The whole subject of " Sight " is divided into a consideration of "how we see" and of " what we see." Mr. Goblet explains, "An inquiry conducted on this principle offers the advantage that we separate at the beginning the only portion open to discussion, namely, the mode of mental appreciation, from that with respect to which no dispute can arise, namely, the mode of the actual constitution of external circumstances. Differences of opinion may exist in the former division, but in the latter we have all the certainty that can be obtained from the concurrent evidence of our senses." This passage reveals, firstly, the definition of " sight " as "the mental appreciation" (of external objects of vision), for which the first sentence of the book, remarking how difficult it is "to see correctly," had already prepared us. We are, therefore, the less surprised to find afterwards that the question of whether we see perspective is not discussed. If asked, Mr. Goblet would at once answer that we do. He would consider the question an absurd one. Strange as it may appear, nowhere is the distinction noticed between what is conveyed in the mere fact of sensation and perception, and its external constitution as afterwards decided by the judgment. It must, however, be admitted that in this use of the word he is consistent.
This passage also reveals a second point worth noticing. "The actual constitution of external circumstances" startles the reader into the expectation that Mr. Goblet believes in our power of knowing objective reality. We think he is about to lead the forlorn hope in support of the "common-sense school." Only once again, however, does the question of the subjectivity or objectivity of our perception reappear, and then only to be dishonoured as unworthy of consideration (p. 14). In fact, Mr. Goblet takes the step of assuming as not requiring proof the real existence of phenomena. These two questions being tabooed, one almost wonders what is left to write about. Mr. Goblet, however, feels no such difficulty.
In entering upon the question of "How we see," or "The mode in which all visible information is accepted by the mind," it is asserted as an evident truism that "only one idea at any moment can be the subject of apprehension. We have no means of apprehending duality but by successive acceptation." Mr. Goblet's object is to prove that all ideas ,are "relative," i. e., that each is sure to possess some quality which will suggest another idea to which it is common. This is simply the doctrine of the suggesting force or association of ideas. Now, of this no proof can be given
other than the ultimate and all-conclusive fact of experience. Belief has here the sufficient and ultimate sanction of all belief — necessity, than which there is no higher justification. However, Mr. Goblet insists upon proving it by argument, and the argument is this :—
" This limitation to succession leads to an important inference. If we are excluded from the recognition of two facts at once, then we cannot have had conferred upon us a positive knowledge of any one phenomenon of mind or matter. A positive knowledge is omniscient, and overleaps the restrictions of time and space. The form of a successive perception would be uncalled for if we knew everything positively If this be so, it is certain we can have no positive knowledge of the circumstances sot before us. And if not a positive knowledge, then everything that mind or matter can present must be ex necessitate constructed for us on a basis of relativeness."
Now, to speak with diffidence where all is obscure, this seems to be arriving, by means of an incoherent argument, from unsound premisses, at a true conclusion ; not that even the conclusion can be satisfactorily ascertained, except from the after context. Moreover, it unfortunately presents a too true sample of the general style of argument. Why separate succession, which as a fact we consider highly doubtful, should be necessary to the argument we do not see. Why it should exclude positive knowledge, the existence of which we affirm without hesitation, or the exclusion of positive knowledge necessitate relativeness, we are also at a loss to understand. As far as we can see, this heterogeneous mass would admit of but one deduction. If we can only apprehend one idea at a time, and that cannot be a positive one, it would be utterly impossible to get a first idea, for we could not know it relatively, we could not know it positively, and, therefore, could not know it at all. But, not being able to know it, we could never know anything. This is no unfair construction, the materials which warrant it are repeated again and again.
Mr. Goblet enters into an inquiry concerning the nature of "Beauty." On this question he is not indulgent to other inquirers, nor, we think, deserves indulgence himself. In the first place, the subject clearly belongs to the second division of the book. We see beauty ; it is not a mode of seeing. In the second place, while he accusesphilosophers of having mistaken the nature of the inquiry, his own method is, we think, unsound, and the result much less satisfactory. Hutcheson places the beautiful in objects in uniformity and simplicity; Hogarth, in fitness, variety, uniformity, simplicity, intricacy, and quantity. Voltaire says, "Le beau eat tres-relatif. Demandez h un crapaudce pie c'est que la beaute, il vousrepondra .que c'est sa feurelle." Alison says, "The sublimity or beauty of form arises altogether from the associations we connect with them.
In colours, white expresses cheerfulness ; black, gloom ; blue, serenity; purple and ermine, dignity ; scarlet, martial qualities." Mr. Goblet, selecting one of the opinions mentioned, that beauty consists in unity, variety, fitness, association, to which he should have added symmetry and colour, considers each separately, and dismisses it as not being sufficient in itself to account for the effect. Now, of the many authorities cited by him, hardly one is in favour of attributing the result to one principle merely. His treatment is, therefore, unfair. The question is, have they each some effect in producing the gratifying sense of beauty, and a greater in combination. This he virtually admits, though excepting fitness.
Even association is a partial contributor, however much the universality of Alison's statement may be condemned.
In the inquiry into "what we see," Mr. Goblet decides upon form, tone, and colour, and proceeds to investigate the relations of form. Tone is the result of the illuminating property of light, dismissing its colouring power for the present. Shade is, of course, the comparative negation of light resulting from the exposure of black, the natural hue of all bodies while unaffected by light. The experience of the eye with reference to the modifications of light and shade, assisted by that of the other senses, enables us to dis tinguish the "form," whether in plane or perspective. Besides "shade," he investigates "high light" and "half tone" under the head of "tone." When Mr. Goblet asserts that we see form, we must remember in what sense he uses the word "see," viz., as including the mental appreciation. He does not allow an intuitive judgment of perspective. But he cannot be said to notice the point as of any importance. We find ourselves,
therefore, able to see the form of bodies by means of the distribution of white light on the black surface. Additional facility of
distinguishing them, however, as well as additional gratification, is afforded by the colouring power of light. Each ray is composed of divisions of red, yellow, and blue light, as well as a thermal element. While in combination, before impact on a body, the
result is a white colour. As the ray impinges on the body, some of this colour is absorbed according to the wants of the body, and the rest is reflected, to be contemplated by the eye. We then call bodies red, green, &c., according as they fail to absorb these colours respectively. Black bodies absorb all the coloured light, white none, and green reflect the blue and yellow more or less, or in different proportions. Thus the various hues and tints are produced. Of course, to every student of physics this, in substance, is sufficiently familiar. The wording, however, of this portion is not so correct. We may doubt if the ordinary meaning of "sight" includes the mental operation or correcting experience of the judgment, and if it does, whether more heads than form, tone, and colour should not have been included in the category. We may also take exception to a use of the word "colour," which includes only the primary colours and all their combinations except white. Still, within a limit every writer has a right to define a word as he likes. Not that, in this case, Mr. Goblet has done more than allow us to imply the definition from the context. But we object to his then accusing other writers of asserting absurdities merely because they understand the same terms in what we consider a leas doubtful comprehension. Mr. Goblet finds fault with some who say that we do not see form. He is very severe upon those who assert we see nothing but colour. He asks, do not they see a snowy landscape or a white tablet (p. 213) ? It is almost incredible that he should fail to perceive that white is with them a colour. It is no doubt very presumptuous in Lord Montboddo to embrace a comprehension of the term " colour" admitting not only white, but black, and of the word " see " including only what meets the eye. Yet it is sufficiently clear that in this wider sense of the words, colour, and colour alone, is what we ultimately do see. Form we see in the plane only as an incident of colour, viz., the limitation of it. Of course, we do not see colour where colour is not. In the perspective we do not know it at all until after repeated comparisons. It seems strange, no doubt, that perspective should be so readily recognized in what is present to the eye as a flat surface. But we can at any time see almost the same effect produced in a mirror. We forget how much instruction is contained in one experiment, and how many more than one we have made. Notwithstanding able treatment of the contrary view, the onus probandi must be held still to lie with the supporters of an intuitive knowledge of distances. Tone also, of however different origin, is only presented to the eye as colour in the wider sense.
Mr. Goblet now considers various incidents of colour, and, by a rather arbitrary method, computes the number of possible ideas of colour at 13,500,000. Then succeeds a nebulous "summary" which is no summary. On the whole, there is good matter in the book, enough, if eliminated and rewritten, to compose a sufficiently readable volume of about half the size.
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