Not many book titles are straightforwardly absurd. But On Everything is one of them. Even more absurdly, the work appeared to a sceptical world in the form of a six-book epic poem, in Latin. Not only is it uncompromisingly all-encompassing in scope, but its mission is nothing short of saving your life. If you have never heard of its author, Lucretius, and are wary of such artistic ambition and hubris, just a brief time with this shocking, stunning poem will render his name unforgettable.

Lucretius’ own title was De rerum natura – literally ‘On the nature of things’, but actually ‘On the birth, nature and workings of all things’. This breadth of branding was no empty posture: Lucretius was convinced that, once our world is understood aright, any problems that life may throw up can be borne with peace – and even pleasure – of mind. His poem is dogmatic in the strict philosophical sense: it propounds the atomic philosophy formulated in Athens around 300 BC by Epicurus. He had taken up the fifth-century theory of Leucippus and Democritus, that all existing matter consists of an infinite number of indivisible, indestructible and invisible particles. Although we now take for granted these un-cuttable (whence a-tomic) entities, the idea of innumerable unseen building blocks of matter was mocked as a crazy delusion in antiquity. Faced with other much less counterintuitive views of the universe, the Greeks and Romans took little notice of these oddballs’ odd balls. Yet for Epicurus, and in turn Lucretius, atoms were crucial to human happiness: once the mysterious world is exposed as the stark dichotomy of matter and void, ruled by the unbending laws of physics, several hard truths follow thick and fast.

Almost all the central tenets of Lucretius’ poem were flagrantly contradictory to the Roman culture of his day – the 50s BC, those creaking last years of the Republic, when giant beasts such as Julius Caesar, Pompey, Cicero and Catullus roamed the earth. First, that we humans are nothing special: we are but an amalgam of atoms created by the chance collisions and coalitions of unseen particles. Although the soul does exist, it too is nothing more than a temporary mesh of atoms. Accordingly, at the end of every mortal life, the union breaks apart and that person’s existence ends, their atoms being taken up to form other matter in the endless cycle of growth and decay. Deprived of any possible afterlife, the single human lifespan is all any individual has to enjoy.

Faced with this sobering fact, Epicureans were told to use their unknowable time wisely. Crucially, they must give up on the gods: the traditional deities do exist somewhere out there, in the gaps between worlds, but they have no interest in or interaction with humans. As a result, religion and superstition are not just pointless because of their complete ineffectuality, but also harmful because of their power to cause mental and even physical pain. After lamenting how the Greek warrior-king Agamemnon could slaughter his daughter Iphigenia in the belief it would placate Artemis and allow his army to sail to Troy, Lucretius delivers the hammer-blow line that Voltaire thought would last until the end of the world: tantum religio potuit suadere malorum, ‘So many evils has religion been able to advance’.

Instead, humans should focus upon living their own lives well. They should, in fact, be hedonists – but not in the sex, drugs and rock ’n’ roll fashion one might suppose. Epicurus and his crowd were no sensuous libertines, and certainly no epicures. (As he once said himself, ‘I spit on luxurious pleasures’.) They identified maximal human pleasure with the entire removal of pain, both mental and physical. Pains of the body must be endured as and when they occur, but pains of the mind are more insidious: they arise from unbridled desires and unfounded fears. Only rational understanding and moderate behaviour can bring about the complete freedom from disturbance (ataraxiā) that affords the highest state of pleasure. This, Lucretius believes, allows men to live ‘lives worthy of the gods’.

Epicureanism was not for the faint of heart. Yet somehow, this bold, inflexible philosophical school managed to propagate itself from Hellenistic Greece through time and space to find some popular support in Rome of the first century BC. Even the elite were piqued: Caesar and Virgil and Horace toyed with Epicureanism in their younger years. Quite how Lucretius came into the fold is unknown: we know effectively nothing of the man’s life. Stranger still is his sidestepping Epicurus’ stern warning that poetry can mislead and harm humans. It is the decision of either a genius or madman to take the 37 tortuous books of Epicurus’ masterwork On Nature (now lost, although papyrus fragments survive at Herculaneum, conveniently carbonised by the eruption of Vesuvius in AD 79) and to forge from them 7,500 verses of the highest technical craft. This love-labour reveals the head of a missionary, and the heart of a fanatic.

The curriculum of De rerum natura flows forth relentlessly and remorselessly. The six books are to be read, and accepted, argument by argument. Their focus begins from the microscopic: Book One draws a hard line between matter and void, before demolishing rival theories of early Greek philosophers. Book Two surveys the motion, shape and structure of atoms and their compounds. Book Three moves up to the visible world, tackling the nature of the human mind and soul, before closing with an impassioned denunciation of our illogical fear of death. Book Four remains in the mortal sphere, exploring bodily senses, sleep, dreams, and sex – climaxing in a satirical, at times unhinged, invective against romantic love. Book Five widens the lens further to explain our planet’s origin, the nature of the seasons, and the evolution of human society. Finally, Book Six looks upwards to the sky to demystify thunder and lightning, before turning to that greatest of ancient nemeses – disease – whose destructive power is demonstrated by a deep dive into the great Athenian plague of 430 BC. And it is with this grim depiction of human suffering and societal collapse that the poem – in the form we have it – reaches its abrupt and chilling end.

The scale of this epic undertaking is immense, and Lucretius was well aware of its novelty and difficulty:

nec me animi fallit Graiorum obscura reperta
difficile inlustrare Latinis versibus esse,
multa novis verbis praesertim cum sit agendum
propter egestatem linguae et rerum novitatem (1.136-9)

‘I’m not unaware of the difficulty of illuminating the obscure discoveries of the Greeks in Latin verse, especially since many need treating with new terms on account of the inadequacy of our language and the novelty of the subject.’

Although he regularly reminds the reader of his artistic originality, Lucretius maintains throughout an almost fundamental adherence to Epicurus’ philosophical gospel. His vibrant verse is fuelled by an almost messianic zeal to convert the reader to Epicurean truth. And although the poem is explicitly addressed to Gaius Memmius, a contemporary politician (and occasional love poet), that figure is mentioned only ten times: the result is that he fades into the background, placing the general reader in Lucretius’ gaze. Almost all second-person references are entirely unspecific – ‘you’, ‘yours’, and stern imperatives to listen, concentrate, think, and learn. The poem takes no prisoners: either adopt its arguments, and your life will be solved; or reject them and guarantee that your brief span of life will be spent in ignorant misery.

The driving mission of De rerum natura is to bring the light of reason to all mortals toiling miserably in the gloom of delusion and ignorance. Lucretius felt that he was playing a paternal role to immature minds:

nam veluti pueri trepidant atque omnia caecis
in tenebris metuunt, sic nos in luce timemus
interdum, nihilo quae sunt metuenda magis quam
quae pueri in tenebris pavitant finguntque futura.
hunc igitur terrorem animi tenebrasque necessest
non radii solis neque lucida tela diei
discutiant, sed naturae species ratioque.
(1.55-61 = 3.87-93 = 6.35-41)

‘For just as children tremble and fear everything in blind darkness, so do we sometimes even in daylight dread things which are no more to be feared than what children quake at and imagine will happen in the dark. This terror and darkness of the mind must be dispelled not by the sun’s rays and the shining darts of daylight, but by study of the appearance and working of nature.’

Elsewhere, he deploys another telling simile (1.932-47 = 4.6-22) that again makes children of his unenlightened readers: he is like a doctor who spreads a cup of medicinal wormwood with honey, so that youngsters are tricked by that initial sweetness to drink down the vessel’s unpleasant contents; so, too, does Lucretius composes mellifluous verses endowed with poetic charm so that the philosophy itself, which (he grants) ‘often appears somewhat off-putting to those who have not experienced it’, is dispensed to the unsuspecting reader.

A famous example of this strategy comes with the poem’s very opening lines, where the goddess Venus is implored to bring peace to the world.

Aeneadum genetrix, hominum divumque voluptas,
alma Venus, caeli subter labentia signa
quae mare navigerum, quae terras frugiferentis
concelebras, per te quoniam genus omne animantum
concipitur visitque exortum lumina solis…
nam tu sola potes tranquilla pace iuvare
mortalis, quoniam belli fera moenera Mauors
armipotens regit, in gremium qui saepe tuum se
reiicit aeterno devictus vulnere amoris. (1.1-5, 31-4)

‘Mother of Aeneas and his offspring, delight of men and gods, nurturing Venus, who beneath the gliding signs of the sky occupy the ship-bearing sea and the crop-bearing earth, since through you every kind of creature is conceived and rises up to look on the light of the sun…

‘For you alone can delight mortals with tranquil peace, since Mars, powerful in battle, rules the savage works of war, who often reclines himself upon your lap overcome by the eternal wound of love.’

To the Roman reader, this ‘Hymn to Venus’ channels the spirit of how an epic poem should begin: a lofty address to a deity in the hope of securing inspiration for poetic composition. As not only the personification of nature and love, but also the mother of Aeneas, the Trojan prince who founded the Roman race, Venus was the exemplary patroness for a poem striving to heal the Eternal City. The more the work’s arguments unfurl, however, the perversity of this de rigueur proem begins to loom large. Why would an Epicurean address a deity when the gods are explicitly said to be deaf to human appeal? How can Venus herself be the creative force of the world, when the world is the accidental product of random atomic movements?

The most common response to this quandary has been to view this heavenly exordium as allegorical, personifying the forces of love and strife that drive the natural world. But it also helps to draw in the uninitiated reader: for someone who had never heard of this ‘Lucretius’ upstart, and had no idea what a poem De rerum natura was going to contain, this was the perfect sugar-coating for the first papyrus roll – a patriotic paean to the goddess all Romans instinctively venerated. And if that reader would continue for just another 150 lines, he would encounter the earth-shattering truths that (i) religion ruins lives, (ii) there is nothing other than matter and void, (iii) nothing can be created from nothing or destroyed into nothing, and (iv) the most important man in human history was Greek. The reader must then choose how to respond: face these new truths or flee back into the shadows of ignorance?

As a poem written in dactylic hexameter verse – the six-foot metre used for epic verse since the time of Homer – the high-flown character of De rerum natura is felt on every page. And, in this disconcerting world of insentient atoms and void, everyone needs a hero. Step forward Epicurus – ‘a man whom neither the reputation of the gods nor thunderbolts nor heaven’s menacing rumbles could restrain’, who ‘marched far beyond the flaming walls of the world and toured through the immeasurable universe in thought and understanding’. As if out of reverence, Lucretius avoids stating his idol’s identity; only once is Epicurus named in the entire poem, around its mid-point (3.1042), where he is listed as the most shocking proof that even the best of men have to die. In the void left by apathetic gods, it is perhaps unsurprising that Lucretius ends up raising his philosophical master to the highest status of all: he declares that Epicurus’ labours and victories exceed those of the divine Hercules. The man, Lucretius gushes, contrary to his entire philosophical system, ‘was a god – a god’ (deus ille fuit, deus). Theory is one thing and practice another: Epicurus was tantamount to a godhead for those followers whose life he changed.

Despite the poem’s mission to rationalise the world through science, it is replete with arrestingly beautiful and tender moments: the primitive wood-dwelling humans battling the forces of nature, the heifer searching for her lost calf, the ebbing life-force of a man while his soul leaves his body, the awesome power of Mount Etna mid-eruption. Lucretius unpicks nature’s threads while in reverie at its wondrous beauty; he is a man in love with a world he knows he will lose. Precisely because he thinks that humans are simply the random creation of blind processes, formed without design and without purpose, and that our world will assuredly break up into trillions of atoms, our very existence is a miracle to be celebrated.

So then: does this book really solve lives? To anyone who accepts its uncompromising convictions, life gains in value from the unique spell of existence it offers. But it is simultaneously robbed of any transcendent significance through being a meaningless, fortuitous compound within an unfeeling universe. Although Lucretius’ prescient physics do explain most universal events, he has alarmingly little to say about how we should live once we come to understand our world’s workings. True, the famous Epicurean injunction, lathe biōsās, ‘live unnoticed’, succinctly characterises the virtuous Epicurean life: the good life should not be spent in the distracting and debilitating sphere of public politics. Instead, philosophical discussion with close friends should be at the central practice, ideally in a community such as Epicurus’ own Athenian kēpos (‘Garden’). But some awkward questions persist. Why, for instance, should death not be feared, if it marks the end of us and the quasi-divine blessedness we have striven to secure? Why should we marry and have a family: for ourselves or for a human race that has no higher purpose? And, just as secularism resonates more than ever in our present age, would not a percipient social observer such as Lucretius see that irreligion creates its own gods, and in turn wreaks its own harms?

Then there is the question of free will, a problem that continues to trouble philosophers, despite every advance in neuropsychology. Simply put, if our atoms interact with one another according to the predetermined and unbreakable physical laws of the universe, how can ‘we’ actually do anything of our own? Why are we not simply carried along, buffeted against our will into unforeseeable deeds? Democritus felt compelled to accept that his atomic universe was deterministic and, thus, that any feeling of free will was a delusion. Seeing the dangers of such a conclusion, Epicurus’ own infamous solution – analogous to modern quantum mechanics – was to tweak the laws of physics ever so slightly. He claimed that any given atom could, at any given moment, ‘swerve’ a minimal amount from its previous linear path: this event, by being random and instituting a new course of motion, severed the deterministic chain of collisions hitherto. But we aren’t out of the woods: just how could an unpredictable atomic event explain the freedom of action that we seem to have? Although Lucretius explicitly declares (2.216–93) that this swerve (clinamen) initiates new action, neither ‘bottom-up’ (random swerve > bodily action) nor ‘top-down’ causation (independent mental decision > atomic swerve > bodily action) seems to work, the first offering no explanation for intentional activity, the latter contravening Epicurean physics by positing the atomic mind as unmoved mover. The problem remains unsolved.

De rerum natura remains a unique work of literature, both for its intellectual bravura and its unparalleled poetic texture. Yet, for all its power and passion, it did not win Lucretius much philosophical success. However, its literary influence upon the greatest Roman poets, Virgil and Horace, was immediate and immense. Even the playful love poet Ovid, writing a generation or two after Lucretius, chose to record a solemn celebration of it: ‘the poems of sublime Lucretius will die only when a single day will consign the world to destruction’ (Amores 1.15.23-4). The poem is mortal, but it will outlast us all. Just as Epicurean atoms are never destroyed, only rearranged, so has Lucretius’ own poem somehow survived destruction. And even if the central problems of life remain unsolved by its lessons, it is salutary for every modern reader to meditate upon the marvellous and bewildering uncertainty of existence.