On the Nature of Things - Part 3
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Part 3

ATOMIC MOTIONS

Now come: I will untangle for thy steps Now by what motions the begetting bodies Of 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 them Wherewith 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 eyes How eld withdraws each object at the end, Albeit the sum is seen to bide the same, Unharmed, because these motes that leave each thing Diminish what they part from, but endow With increase those to which in turn they come, Constraining these to wither in old age, And those to flower at the prime (and yet Biding not long among them). Thus the sum Forever is replenished, and we live As mortals by eternal give and take.

The nations wax, the nations wane away; In a brief s.p.a.ce the generations pa.s.s, And like to runners hand the lamp of life One unto other.

But if thou believe That 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 needs Be borne along, either by weight their own, Or haply by another's blow without.

For, when, in their incessancy so oft They meet and clash, it comes to pa.s.s amain They 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 all These mites of matter are darted round about, Recall to mind how nowhere in the sum Of All exists a bottom,--nowhere is A realm of rest for primal bodies; since (As amply shown and proved by reason sure) s.p.a.ce has no bound nor measure, and extends Unmetered forth in all directions round.

Since this stands certain, thus 'tis out of doubt No rest is rendered to the primal bodies Along the unfathomable inane; but rather, Inveterately plied by motions mixed, Some, at their jamming, bound aback and leave Huge gaps between, and some from off the blow Are hurried about with s.p.a.ces 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 rocks And the brute bulks of iron, and what else Is of their kind...

The rest leap far asunder, far recoil, Leaving huge gaps between: and these supply For 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 eyes Present each moment; for behold whenever The sun's light and the rays, let in, pour down Across dark halls of houses: thou wilt see The many mites in many a manner mixed Amid 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 sort The ceaseless tossing of primordial seeds Amid the mightier void--at least so far As small affair can for a vaster serve, And by example put thee on the spoor Of knowledge. For this reason too 'tis fit Thou turn thy mind the more unto these bodies Which here are witnessed tumbling in the light: Namely, because such tumblings are a sign That motions also of the primal stuff Secret and viewless lurk beneath, behind.

For thou wilt mark here many a speck, impelled By 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 same Primordial seeds of things first move of self, And then those bodies built of unions small And nearest, as it were, unto the powers Of the primeval atoms, are stirred up By 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 we Can mark in sunbeams, though it not appears What blows do urge them.

Herein wonder not How 'tis that, while the seeds of things are all Moving forever, the sum yet seems to stand Supremely still, except in cases where A thing shows motion of its frame as whole.

For far beneath the ken of senses lies The 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, oft Yet hide their motions, when afar from us Along the distant landscape. Often thus, Upon a hillside will the woolly flocks Be cropping their goodly food and creeping about Whither the summons of the gra.s.s, begemmed With 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 sheen Shoots up the sky, and all the fields about Glitter with bra.s.s, and from beneath, a sound Goes forth from feet of stalwart soldiery, And mountain walls, smote by the shouting, send The voices onward to the stars of heaven, And hither and thither darts the cavalry, And of a sudden down the midmost fields Charges with onset stout enough to rock The solid earth: and yet some post there is Up the high mountains, viewed from which they seem To stand--a gleam at rest along the plains.

Now what the speed to matter's atoms given Thou mayest in few, my Memmius, learn from this: When first the dawn is sprinkling with new light The lands, and all the breed of birds abroad Flit round the trackless forests, with liquid notes Filling the regions along the mellow air, We see 'tis forthwith manifest to man How suddenly the risen sun is wont At such an hour to overspread and clothe The whole with its own splendour; but the sun's Warm exhalations and this serene light Travel not down an empty void; and thus They are compelled more slowly to advance, Whilst, as it were, they cleave the waves of air; Nor one by one travel these particles Of the warm exhalations, but are all Entangled and enma.s.sed, whereby at once Each is restrained by each, and from without Checked, till compelled more slowly to advance.

But the primordial atoms with their old Simple solidity, when forth they travel Along the empty void, all undelayed By aught outside them there, and they, each one Being one unit from nature of its parts, Are borne to that one place on which they strive Still to lay hold, must then, beyond a doubt, Outstrip in speed, and be more swiftly borne Than light of sun, and over regions rush, Of s.p.a.ce much vaster, in the self-same time The 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 G.o.ds, In such adjustment to our human ways, Can nature change the seasons of the years, And bring to birth the grains and all of else To 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 feign That G.o.ds have stablished all things but for man, They seem in all ways mightily to lapse From reason's truth: for ev'n if ne'er I knew What seeds primordial are, yet would I dare This to affirm, ev'n from deep judgment based Upon the ways and conduct of the skies-- This to maintain by many a fact besides-- That in no wise the nature of the world For us was builded by a power divine-- So great the faults it stands enc.u.mbered with: The which, my Memmius, later on, for thee We will clear up. Now as to what remains Concerning motions we'll unfold our thought.

Now is the place, meseems, in these affairs To prove for thee this too: nothing corporeal Of its own force can e'er be upward borne, Or upward go--nor let the bodies of flames Deceive thee here: for they engendered are With 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 round The roofs of houses, and swift flame laps up Timber and beam, 'tis then to be supposed They act of own accord, no force beneath To urge them up. 'Tis thus that blood, discharged From out our bodies, spurts its jets aloft And spatters gore. And hast thou never marked With what a force the water will disgorge Timber 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 more The 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 bears Through empty void. Well, in like manner, flames Ought also to be able, when pressed out, Through winds of air to rise aloft, even though The 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 flame Wherever Nature gives a thoroughfare?

How stars and constellations drop to earth, Seest not? Nay, too, the sun from peak of heaven Sheds 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 power Falls likewise down to earth.

In these affairs We wish thee also well aware of this: The atoms, as their own weight bears them down Plumb through the void, at scarce determined times, In scarce determined places, from their course Decline a little--call it, so to speak, Mere changed trend. For were it not their wont Thuswise to swerve, down would they fall, each one, Like drops of rain, through the unbottomed void; And then collisions ne'er could be nor blows Among the primal elements; and thus Nature would never have created aught.

But, if perchance be any that believe The heavier bodies, as more swiftly borne Plumb down the void, are able from above To strike the lighter, thus engendering blows Able to cause those procreant motions, far From 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, because Both bulk of water and the subtle air By no means can r.e.t.a.r.d each thing alike, But give more quick before the heavier weight; But contrariwise the empty void cannot, On any side, at any time, to aught Oppose 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 above Been swift to strike the lighter, gendering strokes Which cause those divers motions, by whose means Nature transacts her work. And so I say, The atoms must a little swerve at times-- But only the least, lest we should seem to feign Motions 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 who Is there can mark by sense that naught can swerve At 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 new In fixed order, and primordial seeds Produce not by their swerving some new start Of 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 will Whereby we step right forward where desire Leads each man on, whereby the same we swerve In motions, not as at some fixed time, Nor at some fixed line of s.p.a.ce, but where The mind itself has urged? For out of doubt In these affairs 'tis each man's will itself That gives the start, and hence throughout our limbs Incipient motions are diffused. Again, Dost thou not see, when, at a point of time, The bars are opened, how the eager strength Of horses cannot forward break as soon As pants their mind to do? For it behooves That 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 gendered From out the heart, aye, verily, proceeds First 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 powers And mighty urge; for then 'tis clear enough All matter of our total body goes, Hurried along, against our own desire-- Until the will has pulled upon the reins And checked it back, throughout our members all; At whose arbitrament indeed sometimes The stock of matter's forced to change its path, Throughout our members and throughout our joints, And, after being forward cast, to be Reined up, whereat it settles back again.

So seest thou not, how, though external force Drive men before, and often make them move, Onward against desire, and headlong s.n.a.t.c.hed, Yet is there something in these b.r.e.a.s.t.s of ours Strong to combat, strong to withstand the same?-- Wherefore no less within the primal seeds Thou must admit, besides all blows and weight, Some other cause of motion, whence derives This power in us inborn, of some free act.-- Since naught from nothing can become, we see.

For weight prevents all things should come to pa.s.s Through blows, as 'twere, by some external force; But that man's mind itself in all it does Hath not a fixed necessity within, Nor is not, like a conquered thing, compelled To bear and suffer,--this state comes to man From that slight swervement of the elements In no fixed line of s.p.a.ce, 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 old And shall the same hereafter evermore.

And what was wont to be begot of old Shall be begotten under selfsame terms And grow and thrive in power, so far as given To each by Nature's changeless, old decrees.

The sum of things there is no power can change, For naught exists outside, to which can flee Out of the world matter of any kind, Nor forth from which a fresh supply can spring, Break in upon the founded world, and change Whole nature of things, and turn their motions about.

ATOMIC FORMS AND THEIR COMBINATIONS

Now come, and next hereafter apprehend What sorts, how vastly different in form, How varied in mult.i.tudinous shapes they are-- These old beginnings of the universe; Not in the sense that only few are furnished With one like form, but rather not at all In general have they likeness each with each, No marvel: since the stock of them's so great That there's no end (as I have taught) nor sum, They must indeed not one and all be marked By equal outline and by shape the same.

Moreover, humankind, and the mute flocks Of scaly creatures swimming in the streams, And joyous herds around, and all the wild, And all the breeds of birds--both those that teem In gladsome regions of the water-haunts, About the river-banks and springs and pools, And those that throng, flitting from tree to tree, Through trackless woods--Go, take which one thou wilt, In any kind: thou wilt discover still Each from the other still unlike in shape.

Nor in no other wise could offspring know Mother, nor mother offspring--which we see They yet can do, distinguished one from other, No less than human beings, by clear signs.

Thus oft before fair temples of the G.o.ds, Beside the incense-burning altars slain, Drops down the yearling calf, from out its breast Breathing warm streams of blood; the orphaned mother, Ranging meanwhile green woodland pastures round, Knows well the footprints, pressed by cloven hoofs, With eyes regarding every spot about, For sight somewhere of youngling gone from her; And, stopping short, filleth the leafy lanes With her complaints; and oft she seeks again Within the stall, pierced by her yearning still.

Nor tender willows, nor dew-quickened gra.s.s, Nor the loved streams that glide along low banks, Can lure her mind and turn the sudden pain; Nor other shapes of calves that graze thereby Distract her mind or lighten pain the least-- So keen her search for something known and hers.

Moreover, tender kids with bleating throats Do know their horned dams, and b.u.t.ting lambs The flocks of sheep, and thus they patter on, Unfailingly each to its proper teat, As nature intends. Lastly, with any grain, Thou'lt see that no one kernel in one kind Is so far like another, that there still Is not in shapes some difference running through.

By a like law we see how earth is pied With sh.e.l.ls and conchs, where, with soft waves, the sea Beats on the thirsty sands of curving sh.o.r.es.

Wherefore again, again, since seeds of things Exist by nature, nor were wrought with hands After a fixed pattern of one other, They needs must flitter to and fro with shapes In types dissimilar to one another.

Easy enough by thought of mind to solve Why fires of lightning more can penetrate Than these of ours from pitch-pine born on earth.

For thou canst say lightning's celestial fire, So subtle, is formed of figures finer far, And pa.s.ses thus through holes which this our fire, Born from the wood, created from the pine, Cannot. Again, light pa.s.ses through the horn On the lantern's side, while rain is dashed away.

And why?--unless those bodies of light should be Finer than those of water's genial showers.

We see how quickly through a colander The wines will flow; how, on the other hand, The sluggish olive-oil delays: no doubt, Because 'tis wrought of elements more large, Or else more crook'd and intertangled. Thus It comes that the primordials cannot be So suddenly sundered one from other, and seep, One through each several hole of anything.

And note, besides, that liquor of honey or milk Yields in the mouth agreeable taste to tongue, Whilst nauseous wormwood, pungent centaury, With their foul flavour set the lips awry; Thus simple 'tis to see that whatsoever Can touch the senses pleasingly are made Of smooth and rounded elements, whilst those Which seem the bitter and the sharp, are held Entwined by elements more crook'd, and so Are wont to tear their ways into our senses, And rend our body as they enter in.

In short all good to sense, all bad to touch, Being up-built of figures so unlike, Are mutually at strife--lest thou suppose That the shrill rasping of a squeaking saw Consists of elements as smooth as song Which, waked by nimble fingers, on the strings The sweet musicians fashion; or suppose That same-shaped atoms through men's nostrils pierce When foul cadavers burn, as when the stage Is with Cilician saffron sprinkled fresh, And the altar near exhales Panchaean scent; Or hold as of like seed the goodly hues Of things which feast our eyes, as those which sting Against the smarting pupil and draw tears, Or show, with gruesome aspect, grim and vile.

For never a shape which charms our sense was made Without some elemental smoothness; whilst Whate'er is harsh and irksome has been framed Still with some roughness in its elements.

Some, too, there are which justly are supposed To be nor smooth nor altogether hooked, With bended barbs, but slightly angled-out, To tickle rather than to wound the sense-- And of which sort is the salt tartar of wine And flavours of the gummed elecampane.

Again, that glowing fire and icy rime Are fanged with teeth unlike whereby to sting Our body's sense, the touch of each gives proof.

For touch--by sacred majesties of G.o.ds!-- Touch is indeed the body's only sense-- Be't that something in-from-outward works, Be't that something in the body born Wounds, or delighteth as it pa.s.ses out Along the procreant paths of Aphrodite; Or be't the seeds by some collision whirl Disordered in the body and confound By tumult and confusion all the sense-- As thou mayst find, if haply with the hand Thyself thou strike thy body's any part.

On which account, the elemental forms Must differ widely, as enabled thus To cause diverse sensations.

And, again, What seems to us the hardened and condensed Must be of atoms among themselves more hooked, Be held compacted deep within, as 'twere By branch-like atoms--of which sort the chief Are diamond stones, despisers of all blows, And stalwart flint and strength of solid iron, And brazen bars, which, budging hard in locks, Do grate and scream. But what are liquid, formed Of fluid body, they indeed must be Of elements more smooth and round--because Their globules severally will not cohere: To suck the poppy-seeds from palm of hand Is quite as easy as drinking water down, And they, once struck, roll like unto the same.

But that thou seest among the things that flow Some bitter, as the brine of ocean is, Is not the least a marvel...

For since 'tis fluid, smooth its atoms are And round, with painful rough ones mixed therein; Yet need not these be held together hooked: In fact, though rough, they're globular besides, Able at once to roll, and rasp the sense.

And that the more thou mayst believe me here, That with smooth elements are mixed the rough (Whence Neptune's salt astringent body comes), There is a means to separate the twain, And thereupon dividedly to see How the sweet water, after filtering through So often underground, flows freshened forth Into some hollow; for it leaves above The primal germs of nauseating brine, Since cling the rough more readily in earth.

Lastly, whatso thou markest to disperse Upon the instant--smoke, and cloud, and flame-- Must not (even though not all of smooth and round) Be yet co-linked with atoms intertwined, That thus they can, without together cleaving, So pierce our body and so bore the rocks.

Whatever we see...

Given to senses, that thou must perceive They're not from linked but pointed elements.

The which now having taught, I will go on To bind thereto a fact to this allied And drawing from this its proof: these primal germs Vary, yet only with finite tale of shapes.

For were these shapes quite infinite, some seeds Would have a body of infinite increase.

For in one seed, in one small frame of any, The shapes can't vary from one another much.

a.s.sume, we'll say, that of three minim parts Consist the primal bodies, or add a few: When, now, by placing all these parts of one At top and bottom, changing lefts and rights, Thou hast with every kind of shift found out What the aspect of shape of its whole body Each new arrangement gives, for what remains, If thou percase wouldst vary its old shapes, New parts must then be added; follows next, If thou percase wouldst vary still its shapes, That by like logic each arrangement still Requires its increment of other parts.