Atomic Motions
Now come: I will untangle for thy stepsNow by what motions the begetting bodiesOf the world-stuff beget the varied world,And then forever resolve it when begot,And by what force they are constrained to this,And what the speed appointed unto themWherewith to travel down the vast inane:Do thou remember to yield thee to my words.For truly matter coheres not, crowds not tight,Since we behold each thing to wane away,And we observe how all flows on and off,As ‘twere, with age-old time, and from our eyesHow eld withdraws each object at the end,Albeit the sum is seen to bide the same,Unharmed, because these motes that leave each thingDiminish what they part from, but endowWith increase those to which in turn they come,Constraining these to wither in old age,And those to flower at the prime (and yetBiding not long among them). Thus the sumForever is replenished, and we liveAs mortals by eternal give and take.The nations wax, the nations wane away;In a brief space the generations pass,And like to runners hand the lamp of lifeOne unto other.
But if thou believeThat the primordial germs of things can stop,And in their stopping give new motions birth,Afar thou wanderest from the road of truth.For since they wander through the void inane,All the primordial germs of things must needsBe borne along, either by weight their own,Or haply by another’s blow without.For, when, in their incessancy so oftThey meet and clash, it comes to pass amainThey leap asunder, face to face: not strange—Being most hard, and solid in their weights,And naught opposing motion, from behind.And that more clearly thou perceive how allThese mites of matter are darted round about,Recall to mind how nowhere in the sumOf All exists a bottom,—nowhere isA realm of rest for primal bodies; since(As amply shown and proved by reason sure)Space has no bound nor measure, and extendsUnmetered forth in all directions round.Since this stands certain, thus ’tis out of doubtNo rest is rendered to the primal bodiesAlong the unfathomable inane; but rather,Inveterately plied by motions mixed,Some, at their jamming, bound aback and leaveHuge gaps between, and some from off the blowAre hurried about with spaces small between.And all which, brought together with slight gaps,In more condensed union bound aback,Linked by their own all inter-tangled shapes,—These form the irrefragable roots of rocksAnd the brute bulks of iron, and what elseIs of their kind…The rest leap far asunder, far recoil,Leaving huge gaps between: and these supplyFor us thin air and splendour-lights of the sun.And many besides wander the mighty void—Cast back from unions of existing things,Nowhere accepted in the universe,And nowise linked in motions to the rest.And of this fact (as I record it here)An image, a type goes on before our eyesPresent each moment; for behold wheneverThe sun’s light and the rays, let in, pour downAcross dark halls of houses: thou wilt seeThe many mites in many a manner mixedAmid a void in the very light of the rays,And battling on, as in eternal strife,And in battalions contending without halt,In meetings, partings, harried up and down.From this thou mayest conjecture of what sortThe ceaseless tossing of primordial seedsAmid the mightier void—at least so farAs small affair can for a vaster serve,And by example put thee on the spoorOf knowledge. For this reason too ’tis fitThou turn thy mind the more unto these bodiesWhich here are witnessed tumbling in the light:Namely, because such tumblings are a signThat motions also of the primal stuffSecret and viewless lurk beneath, behind.For thou wilt mark here many a speck, impelledBy viewless blows, to change its little course,And beaten backwards to return again,Hither and thither in all directions round.Lo, all their shifting movement is of old,From the primeval atoms; for the samePrimordial seeds of things first move of self,And then those bodies built of unions smallAnd nearest, as it were, unto the powersOf the primeval atoms, are stirred upBy impulse of those atoms’ unseen blows,And these thereafter goad the next in size:Thus motion ascends from the primevals on,And stage by stage emerges to our sense,Until those objects also move which weCan mark in sunbeams, though it not appearsWhat blows do urge them.
Herein wonder notHow ’tis that, while the seeds of things are allMoving forever, the sum yet seems to standSupremely still, except in cases whereA thing shows motion of its frame as whole.For far beneath the ken of senses liesThe nature of those ultimates of the world;And so, since those themselves thou canst not see,Their motion also must they veil from men—For mark, indeed, how things we can see, oftYet hide their motions, when afar from usAlong the distant landscape. Often thus,Upon a hillside will the woolly flocksBe cropping their goodly food and creeping aboutWhither the summons of the grass, begemmedWith the fresh dew, is calling, and the lambs,Well filled, are frisking, locking horns in sport:Yet all for us seem blurred and blent afar—A glint of white at rest on a green hill.Again, when mighty legions, marching round,Fill all the quarters of the plains below,Rousing a mimic warfare, there the sheenShoots up the sky, and all the fields aboutGlitter with brass, and from beneath, a soundGoes forth from feet of stalwart soldiery,And mountain walls, smote by the shouting, sendThe voices onward to the stars of heaven,And hither and thither darts the cavalry,And of a sudden down the midmost fieldsCharges with onset stout enough to rockThe solid earth: and yet some post there isUp the high mountains, viewed from which they seemTo stand—a gleam at rest along the plains.
Now what the speed to matter’s atoms givenThou mayest in few, my Memmius, learn from this:When first the dawn is sprinkling with new lightThe lands, and all the breed of birds abroadFlit round the trackless forests, with liquid notesFilling the regions along the mellow air,We see ’tis forthwith manifest to manHow suddenly the risen sun is wontAt such an hour to overspread and clotheThe whole with its own splendour; but the sun’sWarm exhalations and this serene lightTravel not down an empty void; and thusThey are compelled more slowly to advance,Whilst, as it were, they cleave the waves of air;Nor one by one travel these particlesOf the warm exhalations, but are allEntangled and enmassed, whereby at onceEach is restrained by each, and from withoutChecked, till compelled more slowly to advance.But the primordial atoms with their oldSimple solidity, when forth they travelAlong the empty void, all undelayedBy aught outside them there, and they, each oneBeing one unit from nature of its parts,Are borne to that one place on which they striveStill to lay hold, must then, beyond a doubt,Outstrip in speed, and be more swiftly borneThan light of sun, and over regions rush,Of space much vaster, in the self-same timeThe sun’s effulgence widens round the sky.
*****Nor to pursue the atoms one by one,To see the law whereby each thing goes on.But some men, ignorant of matter, think,Opposing this, that not without the gods,In such adjustment to our human ways,Can nature change the seasons of the years,And bring to birth the grains and all of elseTo which divine Delight, the guide of life,Persuades mortality and leads it on,That, through her artful blandishments of love,It propagate the generations still,Lest humankind should perish. When they feignThat gods have stablished all things but for man,They seem in all ways mightily to lapseFrom reason’s truth: for ev’n if ne’er I knewWhat seeds primordial are, yet would I dareThis to affirm, ev’n from deep judgment basedUpon the ways and conduct of the skies—This to maintain by many a fact besides—That in no wise the nature of the worldFor us was builded by a power divine—So great the faults it stands encumbered with:The which, my Memmius, later on, for theeWe will clear up. Now as to what remainsConcerning motions we’ll unfold our thought.
Now is the place, meseems, in these affairsTo prove for thee this too: nothing corporealOf its own force can e’er be upward borne,Or upward go—nor let the bodies of flamesDeceive thee here: for they engendered areWith urge to upwards, taking thus increase,Whereby grow upwards shining grains and trees,Though all the weight within them downward bears.Nor, when the fires will leap from under roundThe roofs of houses, and swift flame laps upTimber and beam, ’tis then to be supposedThey act of own accord, no force beneathTo urge them up. ’Tis thus that blood, dischargedFrom out our bodies, spurts its jets aloftAnd spatters gore. And hast thou never markedWith what a force the water will disgorgeTimber and beam? The deeper, straight and down,We push them in, and, many though we be,The more we press with main and toil, the moreThe water vomits up and flings them back,That, more than half their length, they there emerge,Rebounding. Yet we never doubt, meseems,That all the weight within them downward bearsThrough empty void. Well, in like manner, flamesOught also to be able, when pressed out,Through winds of air to rise aloft, even thoughThe weight within them strive to draw them down.Hast thou not seen, sweeping so far and high,The meteors, midnight flambeaus of the sky,How after them they draw long trails of flameWherever Nature gives a thoroughfare?How stars and constellations drop to earth,Seest not? Nay, too, the sun from peak of heavenSheds round to every quarter its large heat,And sows the new-ploughed intervales with light:Thus also sun’s heat downward tends to earth.Athwart the rain thou seest the lightning fly;Now here, now there, bursting from out the clouds,The fires dash zig-zag—and that flaming powerFalls likewise down to earth.
In these affairsWe wish thee also well aware of this:The atoms, as their own weight bears them downPlumb through the void, at scarce determined times,In scarce determined places, from their courseDecline a little—call it, so to speak,Mere changed trend. For were it not their wontThuswise to swerve, down would they fall, each one,Like drops of rain, through the unbottomed void;And then collisions ne’er could be nor blowsAmong the primal elements; and thusNature would never have created aught.
But, if perchance be any that believeThe heavier bodies, as more swiftly bornePlumb down the void, are able from aboveTo strike the lighter, thus engendering blowsAble to cause those procreant motions, farFrom highways of true reason they retire.For whatsoever through the waters fall,Or through thin air, must quicken their descent,Each after its weight—on this account, becauseBoth bulk of water and the subtle airBy no means can retard each thing alike,But give more quick before the heavier weight;But contrariwise the empty void cannot,On any side, at any time, to aughtOppose resistance, but will ever yield,True to its bent of nature. Wherefore all,With equal speed, though equal not in weight,Must rush, borne downward through the still inane.Thus ne’er at all have heavier from aboveBeen swift to strike the lighter, gendering strokesWhich cause those divers motions, by whose meansNature transacts her work. And so I say,The atoms must a little swerve at times—But only the least, lest we should seem to feignMotions oblique, and fact refute us there.For this we see forthwith is manifest:Whatever the weight, it can’t obliquely go,Down on its headlong journey from above,At least so far as thou canst mark; but whoIs there can mark by sense that naught can swerveAt all aside from off its road’s straight line?
Again, if ev’r all motions are co-linked,And from the old ever arise the newIn fixed order, and primordial seedsProduce not by their swerving some new startOf motion to sunder the covenants of fate,That cause succeed not cause from everlasting,Whence this free will for creatures o’er the lands,Whence is it wrested from the fates,—this willWhereby we step right forward where desireLeads each man on, whereby the same we swerveIn motions, not as at some fixed time,Nor at some fixed line of space, but whereThe mind itself has urged? For out of doubtIn these affairs ’tis each man’s will itselfThat gives the start, and hence throughout our limbsIncipient motions are diffused. Again,Dost thou not see, when, at a point of time,The bars are opened, how the eager strengthOf horses cannot forward break as soonAs pants their mind to do? For it behoovesThat all the stock of matter, through the frame,Be roused, in order that, through every joint,Aroused, it press and follow mind’s desire;So thus thou seest initial motion’s genderedFrom out the heart, aye, verily, proceedsFirst from the spirit’s will, whence at the last’Tis given forth through joints and body entire.Quite otherwise it is, when forth we move,Impelled by a blow of another’s mighty powersAnd mighty urge; for then ’tis clear enoughAll matter of our total body goes,Hurried along, against our own desire—Until the will has pulled upon the reinsAnd checked it back, throughout our members all;At whose arbitrament indeed sometimesThe stock of matter’s forced to change its path,Throughout our members and throughout our joints,And, after being forward cast, to beReined up, whereat it settles back again.So seest thou not, how, though external forceDrive men before, and often make them move,Onward against desire, and headlong snatched,Yet is there something in these breasts of oursStrong to combat, strong to withstand the same?—Wherefore no less within the primal seedsThou must admit, besides all blows and weight,Some other cause of motion, whence derivesThis power in us inborn, of some free act.—Since naught from nothing can become, we see.For weight prevents all things should come to passThrough blows, as ‘twere, by some external force;But that man’s mind itself in all it doesHath not a fixed necessity within,Nor is not, like a conquered thing, compelledTo bear and suffer,—this state comes to manFrom that slight swervement of the elementsIn no fixed line of space, in no fixed time.
Nor ever was the stock of stuff more crammed,Nor ever, again, sundered by bigger gaps:For naught gives increase and naught takes away;On which account, just as they move to-day,The elemental bodies moved of oldAnd shall the same hereafter evermore.And what was wont to be begot of oldShall be begotten under selfsame termsAnd grow and thrive in power, so far as givenTo each by Nature’s changeless, old decrees.The sum of things there is no power can change,For naught exists outside, to which can fleeOut of the world matter of any kind,Nor forth from which a fresh supply can spring,Break in upon the founded world, and changeWhole nature of things, and turn their motions about.