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It will require something [of] more trouble to show, that such examples as I have given of the sublime in the second part are capable of producing a mode of pain, and of being thus allied to terror, and to be accounted for on the same principles. And first of such objects as are great in their dimensions. I speak of visual objects.
 

Sect. XI Why Visual Objects of Great Dimensions Are Sublime

Vision is performed by having a picture, formed by the rays of light which are reflected from the object, painted in one piece, instantaneously, on the retina, or last nervous part of the eye. Or, according to others, there is but one point of any object painted on the eye in such a manner as to be perceived at once; but by moving the eye, we gather up, with great celerity, the several parts of the object, so as to form one uniform piece. If the former opinion be allowed, it will be considered, that though all the light reflected from a large body should strike the eye in one instant; yet we must suppose that the body itself is formed of a vast number of distinct points, every one of which, or the ray from every one, makes an impression on the retina. So that, thought the image of one point should cause but a small tension of this membrane, another and another, and another stroke, must in their progress case a very great one, until it arrives at last to the highest degree; and the whole capacity of the eye, vibrating in all its parts, must approach near to the nature of what causes pain, and consequently must produce an idea of the sublime. Again, if we take it, that one point only of an object is distinguishable at once, the matter will amount nearly to the same thing, or rather it will make the origin of the sublime from greatness of dimension yet clearer. For if but one point is observed at once, the eye must traverse the vast space of such bodies with great quickness, and consequently the fine nerves and muscles destined to the motion of that part must be very much strained; and their great sensibility must make them highly affected by this straining. Besides, it signifies just nothing to the effect produced, whether a body has its parts connected and makes its impression at once; or, making but one impression of a point at a time, causes a succession of the same or others so quickly as to make them seem untied; as is evident from the common effect of whirling about a lighted torch or piece of wood; which, if done with celerity, seems a circle of fire.

Sect. X Unity Why Requisite to Vastness

It may be objected to this theory, that the eye generally receives an equal number of rays at all times, and that therefore a great object cannot affect it by the number of rays, more than that variety of objects which the eye must always discern whilst it remains open. But to this I answer, that admitting an equal number of rays, or an equal quantity of luminous particles, to strike the eye at all times, yet if these rays frequently vary their nature, now to blue, now to red, and so on, or their manner of termination, as to a number of petty squares, triangles, or the like, at every change, whether of color or shape, the organ has a sort of relaxation or rest; but this relaxation and labor so often interrupted, is by no means productive of ease; neither has it the effect of vigorous and uniform labor. Whoever has remarked the different effects of some strong exercise, and some little piddling action, will understand why a teasing, fretful employment, which at once wearies and weakens the body, should have nothing great; these sorts of impulses, which are rather teasing than painful, by continually and suddenly altering their tenor and direction, prevent that full tension, that species of uniform labor which is allied to strong pain, and causes the sublime. The sum total of things of various kinds, though it should equal the number of the uniform parts composing some one entire object, is not equal in its effect upon the organs of our bodies. Besides the one already assigned, there is another very strong reason for the difference. The mind in reality hardly ever can attend diligently to more than one thing at a time; if this thing be little, the effect is little, and a number of other little objects cannot engage the attention; the mind is bound by the bonds of the object; and what is not attended to, and what does not exist, are much the same in effect; but the eye, or the mind, (for in this case there is no difference,) in great, uniform objects does not readily arrive at their bounds; it has no rest whilst it contemplates them; the image is much the same everywhere. So that everything great by its quantity must necessarily be one, simple, entire.
 

Sect. XIII The Effect of Succession in Visual Objects Explained

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As in this discourse we chiefly attach ourselves to the sublime, as it affects the eye, we shall consider particularly why a successive disposition of uniform parts in the same right line should be sublime, and upon what principle this disposition is enabled to make a comparatively small quantity of matter produce a grander effect, than a much larger quantity disposed in another manner. To avoid the perplexity of general notions; let us set before our eyes a colonnade of uniform pillars planted in a right line; let us take our stand in such a manner, that the eye may shoot along this colonnade, for it has its best effect in this view. In our present situation it is plain, that the rays from the first round pillar will cause the eye a vibration of that species; an image of the pillar itself. The pillar immediately succeeding increases it; that which follow it renews and enforces the impression; each in its order as it succeeds, repeats impulse after impulse, and stroke after stroke, until the eye, long exercised in one particular way, cannot lose that object immediately; and, being violently roused by this continued agitation, it presents the mind with a grand or sublime conception. But instead of viewing a rank of uniform pillars, let us suppose that they succeed each other, a round and a square one alternately. In this case the vibration caused by the first round pillar perishes as soon as it is formed; and one of the quite another sort (the square) directly occupies its place; which however, it resigns as quickly to the round one; and thus the eye proceeds, alternately; taking up one image, and laying down another, as long as the building continues. From whence it is obvious, that, at the last pillar, the impression is as far from continuing as it was at the very first; because, in fact, the sensory can receive no distinct impression but from the last; and it can never of itself resume a dissimilar impression: besides, every variation of the object is a rest and relaxation to the organs of sight; and these reliefs prevent that powerful emotion so necessary to produce the sublime. To produce therefore a perfect grandeur in such things as we have been mentioning, there should be a perfect simplicity, an absolute uniformity in disposition, shape, and coloring. Upon this principle of succession and uniformity it may be asked, why a long bare wall should not be a more sublime object than a colonnade; since the succession in no way interrupted; since the eye meets no check; since nothing more uniform can be conceived? A long bare wall is certainly not so grand an object as a colonnade of the same length and height. It is not altogether difficult to account for this difference. When we look at a naked wall, from the evenness of the object, the eye runs along its whole space, and arrives quickly at its termination; the eye meets nothing which may detain it a proper time to produce a very great lasting effect. The view of the bare wall, if it be of a great height and length, is undoubtedly grand; but this is only one idea, and not a repetition of similar ideas: it is therefor great, not so much upon the principle of infinity, as upon that of vastness. But we are not so powerfully affected with any one impulse, unless it be one of a prodigious force indeed, as we anew with as succession of similar impulses; because the nerves of the sensory do not (if I may use the expression) acquire a habit of repeating the same feeling in such a manner as to continue it longer than its cause is in action.
 

Sect. XX Why Smoothness Is Beautiful

It is to explain the true cause of visual beauty, that I call in the assistance of the other senses. If it appear that smoothness is a principle case of pleasure to the touch, taste, smell, and hearing, it will be easily admitted a constituent of visual beauty; especially as we have before shown, that this quality is found almost without exception in all bodies that are by general consent held beautiful. There can be no doubt that bodies which are rough and angular, rouse and vellicate the organs of feeling, causing a sense of pain, which consists in the violent tension or contraction of the muscular fibers. On the contrary, the application of smooth bodies release; gently stroking with a smooth hand allays violent pains and cramps, and relaxes the suffering parts from their unnatural tension; and it has therefore very often no mean effect in removing swellings and obstructions. The sense of feeling is highly gratified with smooth bodies. A bed smoothly laid, and soft, that it share the resistance is very way inconsiderable, is a great luxury, disposing to an universal relaxation, and inducing beyond anything else that species of it called sleep.