On the Nature of Things (De Rerum Natura)
by Titus Lucretius Carus (c. 99 - c. 55 BCE)

This abridged presentation of Lucretius' famous six-book poem on nature focuses mostly on those passages essential to Epicureanism based on translations by Sisson and Rouse. The contents of these files are not public domain, but appear by permission of the copyright holders mentioned in the notices at the bottom of each page -- all rights reserved.  About 50% to 60% of the text from each book is represented here; breaks in the text are demarcated by a numeric heading which corresponds to the line number of the Latin manuscript.

An unabridged public-domain translation is also available at MIT.

Book II


Pleasant it is, when on the great sea, the winds trouble the waters,

to gaze from shore upon another’s great tribulation:

Not because any man’s troubles are a delectable joy,

but because to perceive what ills you are free from yourself is pleasant.

Pleasant is it also to behold great encounters of warfare

arrayed over the plains, with no part of yours in the peril.

But nothing is more delightful than to possess lofty sanctuaries serene,

well fortified by the teachings of the wise,

whence you may look down upon others and behold them all astray

wandering abroad and seeking the path of life:

—the strife of wits, the fight for precedence, all laboring night and day

with surpassing toil to mount upon the pinnacle of riches.

Oh pitiable minds of men, Oh blind intelligences!

In what gloom of life, in how great perils is passed

all your poor span of time not to see that all nature barks for is this:

That pain be removed away out of the body, and that the mind,

kept away from care and fear, enjoy a feeling of delight!


Thus we see that few things altogether

are necessary for the bodily nature,

only such in each case as take pain away,

and can also spread for our use many delights;

Nor does nature herself ever crave anything more pleasurable,

if there be no golden images of youths about the house,

upholding fiery torches in their right hands

that light may be provided for nightly revelings,

if the hall does not shine with silver and glitter with gold,

if no crossbeams paneled and gilded echo the lyre,

when all the same, men can stretch forth in groups

upon the soft grass beside a rill of water under branches of a tall tree

merrily refreshing themselves at no great cost,

especially when the weather smiles, and the season of the year

besprinkles the green herbage with flowers.


And no quicker do hot fevers fly away from your body,

if you have pictured tapestry and blushing purple to toss upon,

than if you must lie sick under the poor man’s blanket.

Therefore, since treasures profit nothing for our body,

nor noble birth nor the glory of royalty,

we must further think that for the mind also they are unprofitable;

Except perhaps in so far as the sight of your army

performing maneuvers especially for your review,

or the spectacle of your fleet putting out in the channel

gives you a moment’s distraction from you religion

and your anxieties at the approach of death

leaving your mind to benefit by its emptiness.


But if you see that such a hope is ridiculous

and that in fact men’s fears and anxieties

are not erased by expensive martial noises,

so that even outrageously powerful political figures

feel them in spite of all the flashing equipment

and even the best padded uniforms cannot deaden them,

how can we doubt that only reason can soothe us

in a life which, after all, is passed in darkness?


For just as children are afraid of the dark,

their elders, as often as not, are afraid in the light

of things which really there is just as little cause to fear

as those with which children contrive to frighten themselves.

These grown-up terrors are also no more than shadows

and yet they are nothing that sunlight can dissipate:

What is needed is the rational study of nature.


So now I will tell you how the generative particles

bring different things into being and then dissolve them,

how they move, what the forces are which control them,

and with what velocity they are propelled through the emptiness:

These are the issues for which I require your attention.


Matter is certainly not glued firmly together,

since everything we see wears out and grows less

so that everything seems to flow away in the end,

concealing its final decrepitude from our eyes

while the universe as a whole somehow goes on.

This is because the particles which escape

from one object attach themselves to another

and so one thing will grow old and another flower.

That is not all: for everything is renewed

and mortals live by preying on one another.

Some kinds of creatures increase, while others diminish;

In a little time there is a new generation,

as the torch is handed on by Olympic runners.


There are those who think that particles can stop moving

and then start again after reaching a point of rest,

but that is an intellectual deviation.

For, since they move through emptiness,

each must be carried along by its own weight

or else by impact from another particle;

For if they hit one another they jump away—

hardly surprising, since they are very hard bodies,

heavy and solid, with no obstructions behind them.


To understand how matter is agitated,

you have to remember the universe has no bottom

nor any other point at which things can stop,

being that space is without limit

—spreading out on every side immeasurably—

a point which has already been fully demonstrated.


With this arrangement, there is no question

of any particle being anywhere at rest in the void,

but all are moved for ever in varying directions.

Some hit and rebound to a considerable distance,

while others recoil but a little way from the shock;

And the ones which are separated by smaller intervals

are those whose shapes are such that they get entangled:

These form the substance of the hardest rocks and of iron

and other things of similar weight and density.

Those particles which jump a long way apart

—and these are, relatively, a small number only—

leaving wide spaces between, make up such substances

as the thin air and the bright rays of the sun.


Many particles wander in the great void,

some of them reject and stray from substances,

having found no group that they could belong to.

A model and image of such wandering particles

is something we have daily before our eyes:

Just look when sunbeams shine in a darkened room;

you will see many tiny objects twisting and turning

and moving here and there where the sunlight shows.

It’s as if they were in an unending conflict

with squadrons coming and going in ceaseless battle,

now forming groups, now scattering, and nothing lasting.

From this you can imagine the agitation

of the genetic particles in the great emptiness,

so far at any rate as so small an example

can give any hint of infinite events.


Or you might say that it is worthwhile to study

the way in which the motes of dust dance in a sunbeam

because the behavior of these tiny objects

gives us a notion of that of invisible particles.

You will see many of these sailing dust-motes

impelled no doubt by collisions one cannot detect,

change direction, and turn off this way or that.

Surely their movement depends on that of the particles.


The particles are of course the first things to move;

Then it is the turn of the smallest groups

which are, so to say, the next in the order of forces

that are shaken by an impulse from the particles

till they in turn hit something a little bigger.

So movement arises from the original particles

and continues in series until it reaches our senses

and we see at last the motes which dance in the sunbeams,

even though at this stage collisions are not perceptible.


Memmius, my next subject is the velocity of particles

and it can be disposed of in very few words.

When first the dawn comes scattering its new light

and the miscellaneous birds, here and there in the woods,

begin to fill the air with their fluid song,

how suddenly does the sun as it rises up

pour its light over everything! This is a spectacle

which we have witnessed over and over again.

And yet the warmth that the sun puts out, and the light,

do not travel in absolute emptiness, there is something to hinder them;


They have to swim, so to speak, through waves of air.

Moreover, the particles of heat do not come singly

but tangled up or joined together in masses;

So they impede one another, and find themselves bumping

against other particles; their travel is relatively slow.

But the original particles, heavy and dense,

traveling through the great emptiness—nothing impedes them

no doubt because they are so much of a unity—

are carried forward without any change of direction.

They must certainly be distinguished for speed

and move much faster than the rays of the sun,

passing over the same distance in much less time

than it takes sunbeams as they move through the sky.



There is something more to be learned about this matter:

As bodies are borne on down through the void by their own weight,

at uncertain times and places, they give way a little

to one side or another in a slight deflection.


If they did not, then everything would fall down,

like drops of rain falling forever through emptiness,

there would be no occasion for encounters of elements

and if one did not strike another there would be no creation.


For if anyone thinks that the heavier bodies could

fall on the lighter, because they fall down more swiftly,

and that this could be the origin of the encounters

which bring about the movements of generations,

they are certainly wandering a long way from the truth.

Anything falling through water or through the air

no doubt must gain in speed as it has more weight

because the body of water and the nature of air

are such that they cannot offer equal resistance

to everything, but give way fast to the heaviest:

But the void has no power of resisting anything

at any time whatsoever or at any place;

Its nature is to give way, and so it does.

It follows that the void is passive and everything falls

through it at equal speed whatever its weight

and therefore there is no question of lighter elements

being fallen upon from above, so having encounters

which might produce the movements required by nature.


It is clear as day that there must be some slight deflection

in elements as they fall, but only the slightest;

We must avoid the suggestion of slantwise motion

for it is a matter of common observation

that heavy bodies do not fall out of the vertical.

If they fall they fall, you have only to look to see this.

Yet to say that nothing suffers the slightest deflection

is to go beyond what observation shows.


Again, if all motion is always one long chain,

and if everything is so determined,

and if the elements could never swerve

so that they break the order of fate

so that cause does not follow cause infinitely,

How would living creatures everywhere come by that freedom

which enables the will to wrench itself loose from fate

and us to go up and down the world as we like?

We change direction not because it is time to do so

or because we are where we must, but because we want to.

Without a doubt, it is our wills that begin these movements

which are carried out through our limbs.

Haven’t you seen, at the moment the barriers open

at the start of a race, the horses, as if hesitating,

unable to throw themselves forward as fast as they want to?

The whole of their matter has to be brought into motion,

which means that the messages have to run through their bodies

till every bit is altered and moves with the mind.

As you see, the impetus comes from within;

The movement starts in the mind and in the will;

From there it spreads through the limbs and through the whole body.


It is not at all the same thing when we move at the instance

of an overpowering force, or simply because someone pushes us.

In that case the material of the whole body

obviously moves in spite of us, hurried onwards

until the will succeeds in curbing it.

The fact is that external forces may move us

and hurry us onwards by the scruff of our necks;

Yet in spite of this, there still is something inside us

which can put up a struggle and get in the way of them.

It is this which controls the material of our bodies

and by a certain adjustment of our limbs

brings them up in their flight and returns them to rest.


There must for this reason be in the elements

some cause of movement other than weights and collisions

from which we could derive our innate free will:

for we know nothing is ever produced from nothing.

The existence of weight means that all is not done by collision,

as it were by external force; but the mind would be reduced

to inner necessities for our very least action

and so defeated as to suffer and bear without choice

if it were not for the tiny swerves which happen to elements

in times and places which are in no way determined.


The total supply of matter was never more close-packed

than it is now, nor was it ever more scattered:

For nothing is added to it or taken away.

And so the movement of elements at the present

is exactly as it has been in times gone by,

which is just the same as it will be in the future:

The way that things have been produced is the way the they will be,

The same conditions of being and growth and strength

as each thing has been given by the law of nature

will continue, and nothing will change the whole of nature.

For there is nothing outside it to which any matter

could make an escape; nor again is there anything anywhere

from which a new force could break in and so change

the course of nature, or disrupt the pattern of movement.


It is nothing to wonder at, when you think about it,

that although the elements are in ceaseless motion

the universe as a whole appears to be stationary

except so afar as particular bodies are moving.

We are dealing with things which are too small for perception

when we speak of elements: and since the bodies themselves

are too small to be seen, so naturally are their movements.

Indeed, with things which are visible, there is concealment,

often of movements, which distance can often erase.

For example, when flocks of sheep are devouring a hillside,

drifting about as the sparkling dew on the pasture

tempts them to this bit or that, while the lambs full of milk

play around the ewes, or amiably butt one another:

All this is completely confused from a distance

and looks like a patch of white on the green of the hill.

In the same way it happens that legions may be on exercise,

filling the plain with an imitation battle,

with cavalry dashing about and making the ground shake;

The flashes of their arms and their armor reaching the sky

and making the earth seem brilliant as well as noisy;

The whole accompanied by vociferous shouting

which echoes from mountains and seems to go up to the starts

yet there will be a place high up in the mountains

from which all this looks like a bring spot on the plain.


Now let us look at the nature of the elements

And how they differ from one another in shape;

You will see that there is extraordinary variety:

Not that the number in any one group is small

But that in general they are not completely alike.

No wonder: since the stock of them is so great,

unlimited, as I have taught—one might say, infinite—

there is plenty of room for variety and it would be odd

if all of them were of identical size and shape.



It is easy enough to explain why a streak of lightning

has so much more penetration than a flame

of the sort which flickers off the top of our torches.

You may say that the fire from the sky is much more subtle

and that the elements it consists of are smaller

so that it easily finds its way through interstices

impermeable by the flame of a torch made of pine.


In the same way light can travel through sheets of horn

but rain cannot: why, if it were not that the elements

which make up light are smaller than those of water?


And wine will run through a strainer as fast as you like

while oil will dawdle and go through drop by drop;

Either the elements making up oil are bigger

or else they are hooked and catch on one another,

which means that they cannot very easily separate

as they have to do in order to go through the mesh

because they must go through the openings one by one.


Or take the case of liquids like honey and milk

which leave a pleasant sensation upon the tongue

in contrast with the bitter flavor of wormwood

or centaury, whose flavor puckers the mouth:

You can easily see that smooth and rounded elements

must form the things agreeable to the taste,

while things which are bitter and rough upon the palate

are composed of hooked and implicated elements

and therefore have to cut their way through our senses

breaking open the organs to find a way in.



Here I would add a refinement to my theory

which follows from what I have said: that the elements

have only a finite variety of shapes.

If it were otherwise, some elements necessarily

would have themselves to be of infinite size.

As long as they are small there is no possibility

of more than a limited variation in shape.

Imagine an element divided in three small parts,

or not much more; then try to arrange those parts

in any manner you will, in a single body.

You can put the top to the bottom or the left or the right

and try any other combination of changes

to produce a modification of the whole shape:

You will soon arrive at the point where, to effect any change,

you will have to add new parts; and if you continue

with new arrangements, you will find for similar reasons

that you will need to add new parts.


You will see that increase of size will follow inevitably

from multiplication of shapes: and you cannot believe

in an infinite variety in the shapes of elements

without admitting that some are of monstrous proportion;

I have shown that this is something you cannot prove.


Why, the brilliant cloths we get from the barbarians,

Meliboean purple, dye from the shells of Thessaly,

the very peacocks with their astonishing beauty

would soon be superseded by other colors;

No one would think anything more of myrrh or honey;

The song of the swans and the sweet sound of stringed instruments

would be surpassed and so reduced to silence

for there would always be something better than they.

Or everything could just as well deteriorate

and you would get the same process in reverse:

Things would become increasingly offensive

to our noses and ears and eyes and to our taste.

But since none of these things happens and there are limits

to what you may experience in either direction

it follows that matter has a fixed number of shapes.


Likewise, from fire to the freezing frosts of winter

is a finite distance, whichever way you look at it;

Between them is every degree of heat and cold

and altogether these make up a perfect series.

So created objects differ in finite ways

since the bounds of their sensible qualities are so marked

at one end by flames, at the other end by hard frost.


To this I would add another not unconnected point;

It is that the number of elemental bodies

which are of similar shape, is bound to be infinite;

For since the number of shapes has been shown to be finite,

it must be, for otherwise you would be asserting

that the supply of matter is limited; which it is not,

as indeed I showed, in a few not ill-sounding verses,

when I was explaining how material elements

out of the infinite hold up the ordered universe

by raining upon it a continuous series of blows.



Another point now from my delightful studies.

You should not suppose the whiteness you see in an object

means whiteness in its elements, or that black objects

come from elements which themselves are black;

Nor indeed, whatever color an object has,

that it is made of elements of that color.

The elements of matter have no color at all,

neither like the objects they form nor yet unlike them.


If you think that colorless bodies are inconceivable,

I can only tell you that you are a long way astray.

For those who are born blind and have never seen

the light of the sun, still know bodies by touch

from the earliest age, with no conjunction of color.

So it is evident that the mind can form

an idea of objects without the assistance of color;

And we ourselves find, touching things in the dark,

that we feel them, though we have no sensation of color.


May I now reinforce the point by a little theory?

Any color can change into any other

—which is not consistent with nature of elements.

There must be something unchangeable in the elements

if everything is not to turn into nothing,

for nothing can change so as to change its nature

without the extinction of what it was before.

Do not therefore attribute color to elements;

You would be on the way to destroying the whole creation.


On the other hand, if you take it there is no color

in elements, but that they are of various shapes

which can produce and change the whole range of colors

and if you go on to attribute a proper importance

to their position and movements and interrelations;

You will find no difficulty in explaining how

something which a moment before was black as coal

should suddenly change and look as white as marble:

As the sea, when tremendous winds have stirred up its waters,

is turned into waves with a white sheen.

You would say that something we often see as black

will, when there is some disorder in its elements

and some are added and some taken away,

appear immediately as shining white.

If the elements of the sea were in fact sea-blue

they could not be white, it is as simple as that:

But however you jumbled them up they would still be blue

and nothing could ever turn them into white.


If it were from elements of various colors

that the pure and uniform skin of the sea was made

in the way that you might construct, for example,

a perfect square out of miscellaneous shapes,

then you would expect, as in the square you could see,

the dissimilar shapes that made it;

So it is in the sea or in any other thing with a uniform surface

that the various contrasting colors make it up.


Besides, with the various shapes which might make a square,

There is no conflict between the part and the whole:

But variety in the colors which make up a surface

are a real impediment to its uniformity.


And anyhow, it does not help the theory

which attributes various colors to elements

if the argument is, not that white things are made of white elements

and black of black, but that both are made from a mixture

because whiteness would certainly be produced more easily

from colorless elements than, let us say, from black

or indeed from any color which is contrary to it.

. And since without light there cannot be any colors

and elements do not emerge in the light at all

it must be that they are in fact without color.

What sort of color can there be in pitch darkness?

Doesn’t color change with the light and in fact depend

on whether the light falls directly or indirectly?

Take a look at a pigeon in the sunlight

and the little feathers about its neck and head;

Sometimes they flash and you might be looking at rubies;

Another time, it may be, the impression you get

is of something between sky-blue and emerald.

A peacock’s tail spread out in a brilliant light

gives off all colors as it turns in the sun.

It is by the fall of light that colors are made

and one cannot conceive that they could exist without it. .

And since what affects the eye is a sort of blow

on the pupil, when it is said to be seeing white,

and so with black and all the other colors;

When you touch something, colors are irrelevant,

the thing that matters about it is the shape:

So one may say that elements don’t need colors;

Their shapes alone give different tactile impressions.


If the colors of elements don’t depend on their shapes

in any rigorous way, but are simply whatever

they turn out to be, without any rhyme or reason,

why then are the things composed of them not equally

apt to take on any color by chance?

You would think you would often see a crow fly by

flapping great wings of the most striking white

and the swans would be black if that’s what their elements were

or take any other color in the same way.


The more a body is divided into small parts

—the more it loses its color, and in the end

you can see the color is put out like a light;

This happens when anyone makes a fine division

of purple, or scarlet, the most brilliant color of all;

Take it thread by thread, the color disappears;

This shows that bits of matter will lose their color

even before you take the division as far as the elements.



Now turn your mind towards the truth of reason.

It is a new matter now that will reach your ears,

something to make the sum of things seem different.

Nothing is ever so easy that it does not seem difficult

the first time you try to take it in,

nor anything so great a wonder that in time

it ceases to cause even the least surprise.

Consider the clear blue color of the sky

and all that it contains, the stars that wander in it,

the moon, the incomparable brightness of the sun:

If all these were presented now to mortals

for the first time and suddenly met their eyes,

could anyone say there was anything more magnificent

or could any nation have dared to imagine such things?

I think not, for it would be such a wonder.

Yet, as it is, people are thoroughly weary of looking at them;

They hardly deign to raise their eyes for the purpose.

Do not, I beg you, be so frightened of novelty

as to reject what is reasonable: sharpen your judgment;

weigh what I say and, and if it strikes you as true,

give in; if false, prepare to come to grips with it.

The mind seeks to understand, in the limitless spaces

extending out beyond the walls of the world,

what may be there for the intelligence to grasp

and so to speak flies through space to see what it is.


First then, in whatever direction you travel from here,

to left or right, upwards or downwards, or any way,

there is no end to the universe. I have said it;

The thing itself shouts it; the nature of space will have it so.

Since that is so, the void spreads out infinitely

and elements in unlimited numbers float

in many ways, driven in endless movement,

can there then be the slightest possibility

that this one globe of earth and this one sky

should be all there is, and the rest of matter do nothing?

Especially as the world is made by nature

and all the elements crashed into one another

in innumerable ways without result or purpose

until at last they were thrown into such conjunctions

as suddenly produced the wonderful world,

the earth, the sea, the sky and all living creatures.

Again and again you are driven to this conclusion:

That there must somewhere else have been other conjunctions

like those which are held here in the jealous grasp of ether.


Besides, wherever there is matter to hand

and place for it, and no cause to prevent it,

the matter must indeed turn into things.

For if the number of elemental bodies

is such that a whole age could not reckon it up

and if the force of nature remains the same

to throw the wandering elements to and fro

in the same way as here, it must be admitted

there are other worlds in other parts of the universe

and other races of men and of wild beasts.


Consider moreover that in the whole of nature

there is not a thing unique and without antecedents

and most must be classified as one of a kind.

Take first of all the animals, you will see it is so.

It is so with the wild beasts roaming in the mountains,

the human race itself, as well as the silent

shoals of fish and the flying creatures.

On the same principle you must admit that the sky,

the earth, the sun, moon, sea and all the rest of it

are not unique, but there are countless numbers of them;

for these are things which have a term to their lives

and which are as dependent on the body

as any creature of an abundant species.


If you keep these things in mind, nature will seem

to be on her own, free of presumptuous masters,

doing everything herself with no help from the gods.

For I appeal to the holy hearts of the gods,

which in tranquil peace pass untroubled days and a life serene:

Who can rule everything? Who can have all space

safe in his hand as if he held a rein?

Who can turn all the skies, or bring enough

ethereal fire to warm up all the fruitful worlds?

Ready in every time and in every place

to make shadows with clouds and shake the skies with thunder?

And then send lightning, which often

strikes on the gods’ own temples, and in desert places

falls pointlessly, and often misses the guilty

to take instead the life of innocent people?


When the world was born, and after the sea’s first day,

after the earth and sun had been formed together,

new matter came to join them from outside;

New elements were thrown in from the great universe:

So sea and earth could grow, and so appeared

the palace of the sky and the high roofs

were built far from the earth and then air came.

For wherever it came from, the great rain of blows

sent every element to the appropriate object;

moisture to moisture and earth added to the earth;

The fire joined up with fire, and ether with ether;

until creative nature finished the job

and bought each substance to its fullest growth

as happens when what passes into the veins of life

is no more than flows out and passes away.

Then is the time when everything comes to a stop

and nature reins back any further increase.

For when anything that you see is growing happily

and gradually, step by step, approaches maturity,

it is taking in more elements than it gives out,

for food is readily taken into its veins

and it is not so laxly made that it loses particles

faster than the ages can replace them.

Of course, our bodies ordinarily lose quite a lot,

that is evident enough: but they take in more

until the day when they reach the summit of growth.

From then on, little by little, age breaks us up

and we flow away to the worse side of things.

The larger anything is—the bigger the surface

once growth has stopped—then the more it scatters around

and elements leave it then in all directions.

Food is no longer easily absorbed in the veins;

Not enough is kept to replace the outflowing tide,

so what is needed to make up the loss

as must be done if there is to be renewal.

All bodies perish when the outflow leaves them rarefied;

They succumb at last to the elements from outside.

Food, sooner or later, is not enough for old age,

the body cannot withstand all the shocks from without

which beat upon in and finally get the better of it.


And so it will be at last with the walls of the world

which are falling into decay in a crumbling ruin.

For it is food which is necessary for renovation

to keep them upright or merely to sustain them;

But the time comes when the veins cannot take in enough

or it may be that nature does not provide enough food.



Already the old plowman shakes his head

to see that all his work has come to nothing:

When he compares the present with the past

he may well praise the fortunes of his father.

He will go on about old times, recalling

how men lived easily on far less land

and plots of ground were smaller;

He does not understand that things grow worse,

that all things move to death, worn out by age.