On the Nature of Things · 15 of 30

Book IV, Part 2

Now come, and why beyond a looking-glass An image may be seen, perceive. For seen It soothly is, removed far within. 'Tis the same sort as objects peered upon Outside in their true shape, whene'er a door Yields through itself an open peering-place, And lets us see so many things outside Beyond the house. Also that sight is made By a twofold twin air: for first is seen The air inside the door-posts; next the doors, The twain to left and right; and afterwards A light beyond comes brushing through our eyes, Then other air, then objects peered upon Outside in their true shape. And thus, when first The image of the glass projects itself, As to our gaze it comes, it shoves ahead And drives along the air that's in the space Betwixt it and our eyes, and brings to pass That we perceive the air ere yet the glass. But when we've also seen the glass itself, Forthwith that image which from us is borne Reaches the glass, and there thrown back again Comes back unto our eyes, and driving rolls Ahead of itself another air, that then 'Tis this we see before itself, and thus It looks so far removed behind the glass. Wherefore again, again, there's naught for wonder

In those which render from the mirror's plane A vision back, since each thing comes to pass By means of the two airs. Now, in the glass The right part of our members is observed Upon the left, because, when comes the image Hitting against the level of the glass, 'Tis not returned unshifted; but forced off Backwards in line direct and not oblique,- Exactly as whoso his plaster-mask Should dash, before 'twere dry, on post or beam, And it should straightway keep, at clinging there, Its shape, reversed, facing him who threw, And so remould the features it gives back: It comes that now the right eye is the left, The left the right. An image too may be From mirror into mirror handed on, Until of idol-films even five or six Have thus been gendered. For whatever things Shall hide back yonder in the house, the same, However far removed in twisting ways, May still be all brought forth through bending paths And by these several mirrors seen to be Within the house, since Nature so compels All things to be borne backward and spring off At equal angles from all other things. To such degree the image gleams across From mirror unto mirror; where 'twas left It comes to be the right, and then again Returns and changes round unto the left. Again, those little sides of mirrors curved Proportionate to the bulge of our own flank Send back to us their idols with the right Upon the right; and this is so because Either the image is passed on along From mirror unto mirror, and thereafter, When twice dashed off, flies back unto ourselves; Or else the image wheels itself around, When once unto the mirror it has come, Since the curved surface teaches it to turn To usward. Further, thou might'st well believe That these film-idols step along with us And set their feet in unison with ours And imitate our carriage, since from that Part of a mirror whence thou hast withdrawn Straightway no images can be returned.

Further, our eye-balls tend to flee the bright And shun to gaze thereon; the sun even blinds, If thou goest on to strain them unto him, Because his strength is mighty, and the films Heavily downward from on high are borne Through the pure ether and the viewless winds, And strike the eyes, disordering their joints. So piecing lustre often burns the eyes, Because it holdeth many seeds of fire Which, working into eyes, engender pain. Again, whatever jaundiced people view Becomes wan-yellow, since from out their bodies Flow many seeds wan-yellow forth to meet The films of things, and many too are mixed Within their eye, which by contagion paint All things with sallowness. Again, we view From dark recesses things that stand in light, Because, when first has entered and possessed The open eyes this nearer darkling air, Swiftly the shining air and luminous Followeth in, which purges then the eyes And scatters asunder of that other air The sable shadows, for in large degrees This air is nimbler, nicer, and more strong. And soon as ever 'thas filled and oped with light The pathways of the eyeballs, which before Black air had blocked, there follow straightaway Those films of things out-standing in the light, Provoking vision- what we cannot do From out the light with objects in the dark, Because that denser darkling air behind Followeth in, and fills each aperture And thus blockades the pathways of the eyes That there no images of any things Can be thrown in and agitate the eyes.

And when from far away we do behold The squared towers of a city, oft Rounded they seem,- on this account because Each distant angle is perceived obtuse, Or rather it is not perceived at all; And perishes its blow nor to our gaze Arrives its stroke, since through such length of air Are borne along the idols that the air Makes blunt the idol of the angle's point By numerous collidings. When thuswise The angles of the tower each and all Have quite escaped the sense, the stones appear As rubbed and rounded on a turner's wheel- Yet not like objects near and truly round, But with a semblance to them, shadowily. Likewise, our shadow in the sun appears To move along and follow our own steps And imitate our carriage- if thou thinkest Air that is thus bereft of light can walk, Following the gait and motion of mankind. For what we use to name a shadow, sure Is naught but air deprived of light. No marvel: Because the earth from spot to spot is reft Progressively of light of sun, whenever In moving round we get within its way, While any spot of earth by us abandoned Is filled with light again, on this account It comes to pass that what was body's shadow Seems still the same to follow after us In one straight course. Since, evermore pour in New lights of rays, and perish then the old, Just like the wool that's drawn into the flame. Therefore the earth is easily spoiled of light And easily refilled and from herself Washeth the black shadows quite away.

And yet in this we don't at all concede That eyes be cheated. For their task it is To note in whatsoever place be light, In what be shadow: whether or no the gleams Be still the same, and whether the shadow which Just now was here is that one passing thither, Or whether the facts be what we said above, 'Tis after all the reasoning of mind That must decide; nor can our eyeballs know The nature of reality. And so Attach thou not this fault of mind to eyes, Nor lightly think our senses everywhere Are tottering. The ship in which we sail Is borne along, although it seems to stand; The ship that bides in roadstead is supposed There to be passing by. And hills and fields Seem fleeing fast astern, past which we urge The ship and fly under the bellying sails. The stars, each one, do seem to pause, affixed To the ethereal caverns, though they all Forever are in motion, rising out And thence revisiting their far descents When they have measured with their bodies bright The span of heaven. And likewise sun and moon Seem biding in a roadstead,- objects which, As plain fact proves, are really borne along. Between two mountains far away aloft From midst the whirl of waters open lies A gaping exit for the fleet, and yet They seem conjoined in a single isle. When boys themselves have stopped their spinning round, The halls still seem to whirl and posts to reel, Until they now must almost think the roofs Threaten to ruin down upon their heads. And now, when Nature begins to lift on high The sun's red splendour and the tremulous fires, And raise him o'er the mountain-tops, those mountains- O'er which he seemeth then to thee to be, His glowing self hard by atingeing them With his own fire- are yet away from us Scarcely two thousand arrow-shots, indeed Oft scarce five hundred courses of a dart; Although between those mountains and the sun Lie the huge plains of ocean spread beneath The vasty shores of ether, and intervene A thousand lands, possessed by many a folk And generations of wild beasts. Again, A pool of water of but a finger's depth, Which lies between the stones along the pave, Offers a vision downward into earth As far, as from the earth o'erspread on high The gulfs of heaven; that thus thou seemest to view Clouds down below and heavenly bodies plunged Wondrously in heaven under earth. Then too, when in the middle of the stream Sticks fast our dashing horse, and down we gaze Into the river's rapid waves, some force Seems then to bear the body of the horse, Though standing still, reversely from his course, And swiftly push up-stream. And wheresoe'er We cast our eyes across, all objects seem Thus to be onward borne and flow along In the same way as we. A portico, Albeit it stands well propped from end to end On equal columns, parallel and big, Contracts by stages in a narrow cone, When from one end the long, long whole is seen,- Until, conjoining ceiling with the floor, And the whole right side with the left, it draws Together to a cone's nigh-viewless point. To sailors on the main the sun he seems From out the waves to rise, and in the waves To set and bury his light- because indeed They gaze on naught but water and the sky. Again, to gazers ignorant of the sea, Vessels in port seem, as with broken poops, To lean upon the water, quite agog; For any portion of the oars that's raised Above the briny spray is straight, and straight The rudders from above. But other parts, Those sunk, immersed below the water-line, Seem broken all and bended and inclined Sloping to upwards, and turned back to float Almost atop the water. And when the winds Carry the scattered drifts along the sky In the night-time, then seem to glide along The radiant constellations 'gainst the clouds And there on high to take far other course From that whereon in truth they're borne. And then, If haply our hand be set beneath one eye And press below thereon, then to our gaze Each object which we gaze on seems to be, By some sensation twain- then twain the lights Of lampions burgeoning in flowers of flame, And twain the furniture in all the house, Two-fold the visages of fellow-men, And twain their bodies. And again, when sleep Has bound our members down in slumber soft And all the body lies in deep repose, Yet then we seem to self to be awake And move our members; and in night's blind gloom We think to mark the daylight and the sun; And, shut within a room, yet still we seem To change our skies, our oceans, rivers, hills, To cross the plains afoot, and hear new sounds, Though still the austere silence of the night Abides around us, and to speak replies, Though voiceless. Other cases of the sort Wondrously many do we see, which all Seek, so to say, to injure faith in sense- In vain, because the largest part of these Deceives through mere opinions of the mind, Which we do add ourselves, feigning to see What by the senses are not seen at all. For naught is harder than to separate Plain facts from dubious, which the mind forthwith Adds by itself. Again, if one suppose That naught is known, he knows not whether this Itself is able to be known, since he Confesses naught to know. Therefore with him I waive discussion- who has set his head Even where his feet should be. But let me grant That this he knows,- I question: whence he knows What 'tis to know and not-to-know in turn, And what created concept of the truth, And what device has proved the dubious To differ from the certain?- since in things He's heretofore seen naught of true. Thou'lt find That from the senses first hath been create Concept of truth, nor can the senses be Rebutted. For criterion must be found Worthy of greater trust, which shall defeat Through own authority the false by true; What, then, than these our senses must there be Worthy a greater trust? Shall reason, sprung From some false sense, prevail to contradict Those senses, sprung as reason wholly is From out of the senses?- For lest these be true, All reason also then is falsified. Or shall the ears have power to blame the eyes, Or yet the touch the ears? Again, shall taste Accuse this touch or shall the nose confute Or eyes defeat it? Methinks not so it is: For unto each has been divided of Its function quite apart, its power to each; And thus we're still constrained to perceive The soft, the cold, the hot apart, apart All divers hues and whatso things there be Conjoined with hues. Likewise the tasting tongue Has its own power apart, and smells apart And sounds apart are known. And thus it is That no one sense can e'er convict another. Nor shall one sense have power to blame itself, Because it always must be deemed the same, Worthy of equal trust. And therefore what At any time unto these senses showed, The same is true. And if the reason be Unable to unravel us the cause Why objects, which at hand were square, afar Seemed rounded, yet it more availeth us, Lacking the reason, to pretend a cause For each configuration, than to let From out our hands escape the obvious things And injure primal faith in sense, and wreck All those foundations upon which do rest Our life and safety. For not only reason Would topple down; but even our very life Would straightaway collapse, unless we dared To trust our senses and to keep away From headlong heights and places to be shunned Of a like peril, and to seek with speed Their opposites! Again, as in a building, If the first plumb-line be askew, and if The square deceiving swerve from lines exact, And if the level waver but the least In any part, the whole construction then Must turn out faulty- shelving and askew, Leaning to back and front, incongruous, That now some portions seem about to fall, And falls the whole ere long- betrayed indeed By first deceiving estimates: so too Thy calculations in affairs of life Must be askew and false, if sprung for thee From senses false. So all that troop of words Marshalled against the senses is quite vain. And now remains to demonstrate with ease How other senses each their things perceive. Firstly, a sound and every voice is heard, When, getting into ears, they strike the sense With their own body. For confess we must Even voice and sound to be corporeal, Because they're able on the sense to strike. Besides voice often scrapes against the throat, And screams in going out do make more rough The wind-pipe- naturally enough, methinks, When, through the narrow exit rising up In larger throng, these primal germs of voice Have thus begun to issue forth. In sooth, Also the door of the mouth is scraped against By air blown outward from distended cheeks.