LUCRETIUS - The Nature Of The Universe - Book VI

November 22 2017


“This dread and darkness of the mind cannot be dispelled by sunbeams, the shining shafts of day, but only by an understanding of the outward form and inner workings of nature.”

This pretty much sums up this final chapter of Lucretius’ great work. This may be my favourite book, for it is as imaginative as it is logical.

“Disturbances of nature: Thunder.”

Lucretius begins with a concept that requires an understanding of Book V’s hypothesis on the order of heavenly objects. As a quick recap: Ether on top, Sun, stars and the moon in the middle, some sky on the bottom.

Clouds, Lucretius starts with, are made of a medium density, less than rocks but more than mist, for they contain ice. Ever so often those clouds clash into each other high up in the ether, driven by opposing winds. The swishing around causes a sound similar to heavy flapping clothes and are known to our sense as thunder claps.

Wind and waves originate from clouds.

Rain is ice that melts within the clouds via lightning that enter the cloud and jumps around in it. If the cloud is drier, lightning ignites a fire which causes a crackling sound to appear.


Dense, bulky clouds contain seeds of fire, due to sun atoms which due to friction from wind are squeezed out of colliding clouds.

“Nature and composition of thunderbolts.”

Thunderbolts too are made of fire. Those fires are composed of more nimble and minute particles than conventional fires and hotter than the rays of the sun.

To produce such a fiery thunderbolt, a cloud must be extremely dense.

The reason why thunder (and its bolts) are more common in spring and autumn is easily explained. In winter, it is too cold for fire to burn and in summer, it is too dry for wind to ignite the fire seeds.

“On the formation of clouds.”

Sudden coalescence. Rough atoms in the upper part of the sky tangle together and glue themselves into clumps, until its time for a storm.

Atoms constantly rise up from the earth, feeding clouds with water from varying sources.

Some atoms also come from the ether and from space. (The idea of “space” is not explained anywhere else. Possibly just farther away ether?)

“The nature of earthquakes.”

According to Lucretius, the earth is full of caves and buried rivers. When those caves collapse, due to strong currents, mountains too, collapse (and cause a shaking of the earth).

If wind rushes through those underground caves, the earth may crack in places.

“Why does nature not grow the sea?”

The simple answer appears to be: because elements. The longer one states that river can’t replenish the ocean because they do not possess sufficient mass, that sun evaporates some of the water, that wind carries some of the droplets away and that some seeps through the semipermeable soil.

“Mount Etna.”

Turns out, the earth can get sick. Its sickness, such as in the case of Mount Etna, is an overabundance of atoms. Mount Etna is hollow, with basaltic caverns which are filled with air and wind. When the air is heated up enough by the wind and atoms it carries, a fire ignites and blazes out.

“Some phenomena have multiple causes. Firstly, The Nile.”

Unlike any other river, the Nile floods Egypt in the summer. Why, Lucretius is not quite certain. He proposes that it may be the special winds there or sand is surrounding the Nile too much and it overflows or perhaps it rains more around the Nile or the snow that melts in the Ethiopian highlands flows into it. Or a combination of those.

“Avernus and other poisonous lakes.”

The earth exudes certain bad vapours which kill birds. Why seems unclear.

“Why is well water warmer in winter and cooler in summer?”

This is one of those things that most modern people couldn’t judge. When was the last time you used a well in either season?

Lucretius helps us out however, by explaining that during the summer months the earth relaxes and expels atoms into the air, cooling the well water.

During the winter the earth tenses up and squeezes heat into wells. This is also the reason why many bodies of water do not freeze over fully.


Firstly, Lucretius provides us with a cool fact: magnets are named for a place, Magnesia, in Greece. Who knew?

Secondly, all visible objects emit perpetual streams of particles, which is why we see (and otherwise discern) them at all. These particles are structured very loosely, a mixture of matter and vacuity. All atoms, he continues, must be polar opposites. Magnets must exude dense streams of atoms which dispel all air between iron and the magnet. The iron atoms then tumble into the void (between the iron and the magnet) and then the iron follows.

All this is helped by air pushing the object into the vacuum.

This all only works on iron because gold is too atomically heavy and wood too porous.

“When the textures of two substances are mutually contrary, so that hollows in the one correspond to projections in the other and vice versa, then the connexion between them is the most perfect.”

“The nature of epidemics.”

This is Lucretius’ last point in his entire work. It is interesting that he leaves with such a gloomy subject but then again fitting for death is the destination for all of us and a fear of death foolish to the true Epicurean. Death, Lucretius and all followers of Epicureanism will argue, is but annihilation - and one cannot regret or fear what one cannot experience. So be merry all, for death is final.

Epidemics occur when atoms upset the equilibrium in the atmosphere. If one travels and falls sick, it is because one is not used to the different atoms in the air. He observes and believes that Elephantiasis is unique to Egypt, gout of the feet to Attica and poor eyes to Achaia. For some reason, he also believes black people are black due to their skin being burnt by the sun. A variation of air, makes for varying conditions.

Lucretius goes on to clinically describe the events of the Athenian plague of 430 BC (This is notable, because this event occurs quite before Lucretius time. He lived between 99-55 BC).

The following symptoms were present:

  1. Fever
  2. Bloodshot eyes
  3. Blacking of the throat and blood in the same
  4. Ulcers of the throat
  5. Bleeding of the tongue
  6. Chest and heart infections
  7. Rotting breath
  8. Generalized decay
  9. Vomitting and a reddening of the skin
  10. Unquenchable thirst

Death occurs after 8 to 9 days.

Some sufferers castrated themselves to survive (he does not elaborate), some survived but without their hands, feet or mind intact. Animals perished as well and even vultures would not go for the corpses.

Victims suffered from depression from the onset of the plague.

“In this hour reverence and worship of the gods carried little weight: they were banished by the immediacy of suffering.”

As abruptly as this, Lucretius leaves us to ponder life, death and especially how to go about both.