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 VI


The first to bring grain to uneasy mortals

in times past was the famous city of Athens

which made life anew and instituted laws:

And first brought delicious consolation to life

when she gave birth to the man of genius so extraordinary

that everything came from a mouth devoted to truth

so that, even though now he is dead, his divine discoveries

spread abroad, carrying his glory to the sky.


For when he saw that whatever men’s needs demanded,

so far as may be, to keep their lives in safety,

was there at hand already for their use,

that men had all they could want in the way of wealth

and honor and praise, and pride in successful children;

Yet, at home each was perpetually disquieted

and the mind was enslaved by all its bitter complaints;

He understood that the trouble was in the container

and because of some flaw in it, everything would go bad

whatever excellent things were put into it:

Partly because there were holes and things flowed through them

and there was no possibility of filling it up;

And partly because what did get in was spoiled,

so to speak, by the nauseous taste there was inside.


The truth was what he used to purify hearts with

and he set a limit to fear as to desire;

He explained what it is that all of us really want

and showed us the way along a little path

which makes it possible for us to go straight there;

He showed what evils there are in human affairs

and how they were brought about by the force of nature,

popping up by change or because nature worked that way;

And he showed how best to face each of these difficulties

and proved that the human race was generally vain

in the way it ruminated in its gloomy thoughts.

For just as children are afraid of the dark

their elders are as often as not afraid in the light

of things which there is as little cause to fear

as those which children imagine to frighten themselves.

These grown-up terrors are also no more than shadows

and yet they are nothing that the sunlight can dissipate:

What is needed is the rational study of nature

and that is why I want to continue this discourse.


Since I have explained that the structure of the world

is mortal and that the heavens must begin and end;

And have made clear most of what happens or can happen

in the universe, now listen to what remains.

When once I get into my poetic chariot,

I have every hope of arriving. Oh, there are obstacles,

but I turn them upside-down with my inspiration.


There are other phenomena men perceive in the universe

which often cause their minds acute suspense

and make them cringe before the fear of the gods,

pressing themselves to the ground, because ignorance

of the causes forces them to attribute everything

to the power of the gods, who, they suppose, are in charge.

Even those who have taken the point that the gods are indifferent

sometimes wonder how the whole affair is managed

and are especially concerned about things above them

which they see rolling around so high in the heavens.

Once more they revert to the ancient superstitions

and take those terrible masters they think all-powerful,

not knowing that there are some things which can happen

and some which cannot, that every power is limited

by the system itself, and that everything has an end.

Their reason is blind and leads them wandering on.


Unless you put out of your head any suggestion

that the gods have attributes inconsistent with their peace,

they—since you have made light of their sanctified powers—

will do you harm: not that the power of the gods

can be so outraged that they will want to punish you,

but you will imagine that they, who are really at peace,

can find themselves rolling in billows of anger,

nor will you be able to receive in suitable peace

the images which flow from their holy bodies

into men’s minds and announce the shape of divinity.

So you see to what kind of life such thoughts will lead you.


Though I have issued many reflections already,

there is still much I must put into this elegant verse

if the truest reason is to drive such thoughts away.

We must grasp the meaning of certain heavenly phenomena;

My poem must touch upon storms and flashes of lightning,

their effects, as well as the causes which bring them about.



There is lightning when the clouds as they clash together

strike out elements of fire, as when stone strikes on stone

or on iron, for you see the light spring out then

and fire scatter itself in brilliant sparks.

But our ears perceive the thunder only after

the eyes have seen the lightning, for sounds always move

more slowly than things which present themselves to the eye.

You can see that, watching from a distance while someone

strikes a tree with an ax; you will see the blow fall

before the sound of it strikes upon your ears.

Exactly the same with lightning, which we see

before we hear the thunder; they occur together

produced by a single cause, the collision of clouds.


As to how places are suddenly tinged

by lightning from the clouds’ quick, tempestuous flashes:

When the wind has gone into a cloud and turned about

making it hollow and thickening up the walls

as I have explained, the cloud grows hot from the movement,

as everything does until it bursts into flame;

A ball of lead which goes far will spin till it melts.

So the wind, grown hot, when cutting through a black cloud,

scatters elements of fire pressed out by the force;

It is these which produce the winking flashes of flame:

Then the sound follows, which is slower to reach the ears

than the visible matter is to reach the eye.

This happens when clouds are closely packed and piled

high about one another in a great cumulus.



Now how does it come into being? And how does it get

the force that enables it to crack strong towers?

To throw down houses and tear up beams and rafters?

To heave up and shift the public monuments?

To seek out men and strike them down like cattle?

How does it manage to do such things as this?

I will proceed at once with my explanation.

Lightning must come from the densest clouds

when they are piled up high: for it never comes

from a clear sky or when the clouds are light.

The matter is clear enough from the manifest facts:

It comes when the clouds pile up in all directions

across the sky, and we think that the shadows of Acheron

have filled up all the hollows of the sky:

A terrifying night seems to have begun

and the faces of black fear are hanging over us

when the storm begins to gather it thunderbolts.


It often happens that a black cloud over the sea

falls into the waves like a river of pitch

and is carried on with its shadows, bring with it

a black storm heavy with lightning and squalls,

itself being first of all full of fire and winds;

So that men on shore are afraid and make for shelter.

We must conclude that the storm above our heads

has deep reaches. How otherwise would such blackness

cover the earth, if clouds were not built up

so as to cause the sun to disappear:

And how could such rains fall from these same clouds

to make rivers overflow and flood the plains

If the structure of clouds did not reach far into the ether?



It is in autumn with all its shining stars

that heaven and earth are most often shaken by lightning

and in the spring when all the flowers are out.

Winter lacks fire and summer has few winds

and the clouds at that time are hardly think enough.

When the seasons are between the two extremes

all the causes of thunder are found together.

Those passages of the year have both cold and heat:

Both of which are needed for the making of thunder,

for that discord of nature in which the furious air

rises in roaring waves of fires and winds.


The first hint of the heat and the last of the cold

is the time of spring: things so dissimilar

must be in conflict and there must be confusion.

And the last of the heat, mixed with the first of the cold,

Brings us to the season which we call autumn;

That is why these two periods are so rough.

No wonder at such times there is often thunder

and troublesome storms drive up and down the sky

since these are times when both sides are stirred to battle,

flames on one side, on the other winds mixed with water.


This is the way to see the nature of thunder

and to understand how it produces its effects,

and not by reading books of Etruscan saws

to find out exactly what the gods are up to,

where they have sent their fire from, or in what direction

it has turned, or in what manner it has entered

behind closed doors, done what it will, and escaped,

or what disasters from heaven thunder can bring.


If it is Jupiter and the other gods

who shake the glittering sky with their terrible crashes

and if they can hurl their fires wherever they like

why don’t they strike at people who have committed

revolting crimes and make them spew out flames,

sticking them through the middle and make examples of them?

Why must it be instead the innocent,

people whose consciences are as clear as noon-day,

who get caught up in the whirlwind of heavenly fire?


And why do they bother to throw their bolts in the desert?

Is it for exercise and to tone up their muscles?

Why do they waste their ammunition on earth

instead of keeping it for the Old Man’s enemies?


And then, why is it never from a clear sky

that Jupiter throws his bolts and makes his noise?

Perhaps he waits will the clouds provide him with cover

to go down himself and take his aim from close quarters?

Then why does he hit the sea? Has he something against

the waves, or finds so much water not to his taste?


Again, if he wants us to get out of the way,

why won’t he let us see where he’s going to throw?

Or if he wants to catch us unawares,

why does he make so much noise that we have warning?

Why does he start with darkness and rumbling and grumbling?


And how does he manage to throw from so many directions

at the same time? It would be very rash to assert

that several bolts have never been loosed simultaneously.

It happens often enough, indeed it must happen

that just as rain falls in a number of places

at the same time, there can be several thunderbolts.


Lastly, why does he choose to smash up sanctuaries,

even his own shrines, with his fatal bolts?

Make cracks in the statues of the gods from top to toe?

And even strike images put up in his honor?

Why does he go for high places, why do we so often

see evidence of his fire on the tops of mountains?



There are phenomena for which it is not sufficient

to state one cause, though only one will be true.

For example, if from a considerable distance

you see a corpse on the ground, it is by running over

the possible causes of death you will find the true one.

You cannot say whether the man has died by the sword,

through the cold, by sickness or perhaps by poison;

What we do know is that he must have died by one of them.

This method will serve us in a number of matters.


The Nile rises in summer and floods the fields,

the only river in Egypt which so behaves.

It irrigates Egypt when the weather is hottest,

perhaps because in summer there are north winds

blowing against it mouth—what they call the etesians

and they drive back the water or hold it back

so that it fills the channel and keeps it still:

For certainly these winds blow upstream; they come

indeed form the icy region about the pole:

The river comes from the south, from a heat-laden country,

through the races of men who are baked black by the sun,

and rises far away where the sun stands highest.


It is possible too that an accumulation of sand

is caused by the waves which push against the current

when the sea driven by the wind throws the sand inshore.

That would have the effect of barring the river’s way

and making the descent of the water less rapid.


It is possible also that at this season the rains

are heavier at its source, for this is the time

when the north winds blow the clouds into that region:

When they are gathered there in the south they are

driven against the high mountains and so to speak jammed there

which results in their being pressed so that rain is squeezed out.


Perhaps also the river collects its water

high up in the mountains of Ethiopia

where the sun shines on the snows and they melt down.



Another matter: I will explain on what principles

it is possible that the power of attracting iron

should reside in the stone which the Greeks call the magnet

because it comes from the country around Magnesia.

This stone is another wonder: it can hold a chain

of several rings without any other support;

You can sometimes see as many as five or more,

one below the other and moving in a light draught;

The first holds the second, the second the next, and so on,

each taking the tying force of the stone from the other

for the power of the magnet penetrates in this way.



It is not at all difficult to demonstrate

the way in which iron is attracted by a magnet.

In the first place, there must flow from the stone

a vast number of elements which push aside

the air between the iron and the stone itself.

With this space emptied, a considerable vacuum is formed

between the two, and the elements of the iron

fall into it in a crowd; the effect of that is

that the ring itself follows, for the whole mass of iron moves.

No substance has its primal elements

more closely impacted than those of iron

which is icy by nature. The less reason for astonishment,

as I said before, that a body of its elements

cannot leave the iron to flow into the vacuum

without the ring following. It follows until it arrives

at the stone, to which it adheres by invisible ties.

This can happen in any direction in which the vacuum

is created, either from one side or from above:

The neighboring elements are carried into it at one;

Not capable themselves of rising in the air,

they are set in motion by bombardment from elsewhere.

What renders this account the more probable

is that existence of another factor which helps movement.

As soon as the air opposite the ring has become rarefied

and a vacuum has been created in the intervening space,

the air behind the ring, so to speak, pushes it forward.

Objects are always bombarded by the air around them;

In the present case this can drive the iron forward

because there is an empty space ready to receive it.

The air accordingly pushes its way against the iron

and indeed into the recesses of its smallest parts

and so drives it forward as wind does the sails of a ship.


Finally every substance has air in its structure

because everything has interstices in it and air

surrounds and is in contract with everything.

In this case therefore, the air concealed in the iron

is stirred up and becomes extremely restless

and no doubt strikes against the ring from inside.

This gives a new impulsion in the direction

in which it was already moving, drawn by the vacuum.


Sometimes the iron is repelled by the stone;

Its habit is to fly from and follow it in turn.

I have seen iron rings from Samothrace leap up at a touch

and also iron filing dance about

in a brass basin when a magnet has been placed underneath,

so anxious does the iron seem to get away.

This disturbance is caused by the interposition of brass;

No wonder, for emanations from that metal

get to the pores of the iron ahead of those

which come from the magnet, and when they arrive

they find everything full and no way in.

They are therefore forced to smash against the surface of the iron

and to beat upon: the magnet repels the iron

and agitates through the brass the metal it would otherwise attract.


It is not surprising that the emanations

coming from the stone do not act the same way on other things.

Some things resist because of their weight, as gold does,

some because their substance is not dense enough and the emanations

go through without touching and so push upon nothing:

Wood appears to be a substance of this kind.

Iron is somewhere between the two;

It needs only a few elements of brass to acquire

the property of responding to magnetic influence.


These phenomena are not so altogether singular

that I could not think of non-metallic materials

which are especially suited to join with one another.

Only lime, for example, will hold stones together;

Glue made of bull’s flesh sticks wood so fast

that the pieces will often crack along the grain

before the glue can be persuaded to relax its hold.

The juice of the grape mixes freely with spring water

while pitch is too heavy and oil too light to do so.

Purple dye from shellfish unites so closely with wool

that it is impossible to get it out,

not if you were to let the waves beat upon it

—a whole sea would not be enough to wash it out.

There is only one substance which will fasten gold to gold

and will anything except tin serve to solder brass?

How many other examples I could produce!

No need to waste time by long-windedness;

It is not necessary to linger on a subject

which I can sum up in a very few words:

Things of which the textures correspond with one another

so that the hollows of one fit the projections of the other,

fit one another best and form the closest unions.

There are also things which fit like hooks and eyes

and hold themselves together in that way:

This seems to be the case with iron and the magnet.


Now I will explain how diseases are caused.

Where does it come from, this morbid force which can blow

disaster together to strike at people and cattle?

The elements of many things, I have shown already,

are beneficial and need to keep life going:

But there must be many others flying about

which bring death and disease. When many of these

have by chance collected, the air itself will sicken.

All this force of sickness, all this pestilence,

comes either from outside as clouds and mists

come down through the sky, or else rises out of the ground

when it is wet and putrefies at a time

of unseasonable rains combined with a blazing sun.


Have you noticed how people far from their homes and countries

are affected by the change in weather and water

and how unlike these may be in different places?

What a difference between the sky they have in Britain

and that in Egypt where the earth slopes down!

Or between Pontus and Gades, and so on till you reach

the black races which have been baked in the sun!

We see four climates as different from each other

as the four winds and the quarters of the sky;

there are also men who differ in color and looks

and diseases which attack the different races.


There is elephant disease which is generated

on the banks of the Nile in Egypt, and nowhere else.

In Attica it is feet which are affected,

in Achaea, eyes; so different places are harmful

to different parts of the body: it is a matter of air.

As soon as a sort of weather that does not suit us

is put in motion and a hurtful air creeps out

like mist and loud, it upsets all in its course

and, bringing change, when at last it reaches our climate

it makes our air like itself and so turns it against us.


Then suddenly there is disaster and pestilence.

It falls on the water or else attacks the crops

or other food or fodder of men and beasts:

Or else its power hangs in the air

and when in breathing we draw in this air

the disease itself is inevitably taken in.

It is the same with diseases which overtake

cattle or cause the flocks of sheep to sicken.

It makes no difference whether we go to places

which do not suit us, and so change the sky which cloaks us,

Or whether the noxious atmosphere comes to us;

Or something else comes we are not accustomed to

which can affect us when it reaches us first.

This sort of disease came like a tide of death

carrying disaster over the Athenian fields,

made roads deserted and emptied the city of people.

Coming from deep within Egypt where it arose,

traveling far through the air over swimming fields,

it came to rest upon the people of Pandion

so they went down in troops to disease and death.


The first symptom was a burning in the head

and both eyes swimming in a red light.

The throat, blackened inside, would sweat with blood,

the way the voice should have come was choked with ulcers,

the tongue, which should speak for the mind, was bleeding and clotted,

weakened with pain, heavy in movement, rough to the touch.

Then through the throat the disease went on to the chest

and flowed into the sad heart of the sufferer;

Then all that kept life in would seem to give way.

Out of the mouth there came a fetid odor

like that which comes from a corpse thrown out and rotting;

Then all the strength of the mind went and the body

languished already on the threshold of death.

Unbearable pains were followed by fearful choking

and they complained and moaned as far as they could;

Night and day there were recurrent spasms

shaking the muscles and the whole organism,

breaking and wearying men already exhausted.

Yet nobody’s skin seemed to be burning unduly,

if you touched it with the hands it seemed rather tepid;

But at the same time there were ulcers all over body,

which looked inflamed as if burnt with the holy fire.

And the inner parts were in flames to the very bones;

A flame blazed in the stomach as in a furnace.

There was nothing so light or thin that it soothed the body,

only wind and cold: some plunged their burning limbs

into icy rivers or naked into the sea;

Many threw themselves headlong into wells

and arrived at the water with their mouths hanging open.

An insatiable thirst drowning their arid bodies

made them think a deluge nothing but a few drops.

There was no respite from pain: their bodies lay fainting,

the doctors muttered and did not know what to say:

They were frightened of so many open, burning eyes

turning towards them because they could not sleep.

There were many other signs of approaching death;

There were minds disturbed with suffering and fear,

sad brows, faces which had grown furious and sharp,

ears into which some sound was always drumming;

The breathing was quick or else deep and hesitant;

A shining torrent of sweat over the neck,

spittle thin and tiny, of a yellowish color,

salty, and scarcely brought up by the hoarse cough.

The sinews of hand contracted, the whole body trembled;

From the feet upwards the cold began to creep

and could not be stopped: at the last moment the nostrils

grew pinched and the point of the nose was sharp and thin;

The eyes were hollowed, the brow hollow; the skin was cold,

hard, the mouth grimaced, the tense brow stood out.

It was not long before they died and stiffened;

As dawn began to break on the eighth day

or perhaps the ninth, they parted with their lives.

If any—as some did—escaped from death

it was with foul ulcers and black diarrhea

while wasting and death still waited for them;

Or, with pains in the head, corrupted blood

would flow continually from the choked nostrils;

And so the body itself would flow away.

If anyone escaped the discharge of nauseous blood

the disease went into his sinews and his joints

and finally the sexual organs themselves.

Some, afraid of crossing the threshold of death,

survived by taking a knife to their sexual parts;

Some remained alive but lost both hands and feet,

with others it was the eyes which had to go;

To such an extent were they afraid of death.

And some of them were so taken with forgetfulness,

that they could not even remember their own names.


Unburied bodies lay one on top of another

yet the birds and wild beasts kept themselves at a distance

because of the stench, or tasted the meat and died.

There was hardly a bird to be seen at all in those days

and the sullen animals would not come out of the forest;

Many of them took the foul disease and died.

The dogs who were faithful were the first to go,

they lay in the streets everywhere, panting and dying

as if the disease was twisting life out of their bodies.

Unaccompanied funerals hurried from every corner.

No remedy could be trusted; if there was anything

which served to keep one breathing and watching the sky

it was sure to be the way out to death for others.

What was most pitiful in this calamity

was that as soon as anyone saw himself touched

by the disease he considered himself condemned;

Failing at once he prostrated himself without courage,

seeing his funeral, and gave up his breath on the spot.

There indeed had to be funeral after funeral;

at no time did the contagion of the plague

cease to lay hands on one person after another

as if it were passing cattle or sheep through a gate.

Those who refused to face the sick in their households,

caring too much for life and afraid of death,

were soon punished by dying shamefully

in pain, deserted, helpless and disregarded.

Those who stayed near at hand died from contagion

and the tasks which they had been forced to undertake

by shame, or by gentle or complaining voices.

So that was how the best of them ended their days.


One upon another, as they struggled to bury the crowd

of their dead, they came back worn out with tears

and many of them took to their beds in grief.

At such a time there was no one unaffected,

If not by plague or death then at least by mourning.

Even the shepherds and the cattlemen

and the tough bodies who usually follow the plow

fell sick and shoved together in a hut,

found death in poverty as well as disease.

On top of the lifeless children you could see

lifeless parents, and sometimes on mothers and fathers

children on the point of giving up life.

In no small part the plague came flowing in

from the fields to the town, brought in by the country people

making their way from all sides as they sickened.

They filled all the houses and all the public places

and the concentrated infection left them in heaps.

Many, prostrated by thirst, crawled through the streets

and lay down by the Silenus heads at the fountain

only to choke on finding so much sweet water.

You would see many others as they went through the streets,

their limbs drooping against their half-dead bodies,

stinking, in rags, dying in their own filth:

Nothing but skin and bones, and with their ulcers

and the much that came from them almost buried already.


As for the holy sanctuaries of the gods,

death had filled them up with corpses. Everywhere

the temples of the divinities were piled with bodies

the guardians having filled them with their guests.

Neither the worship of the gods nor the gods themselves

mattered anymore: the present pain was enough.

Nobody thought any more of the ancient rites

which had been observed in the city when people were buried.

All was confusion and perturbation and everyone

buried the corpse on his hands as best he could.

Poverty and necessity are persuasive.

Some people would push the bodies of their family

on to funeral piles intended for someone else

and set a light to them, all this with shouts

and bloody scuffles before they abandoned the bodies.