Death is nothing to us: does the mortal soul and the symmetry with the time before birth dissolve the fear of death, or does Book III argue against the love of life itself?

Lucretius, answered from the texts and cited to the page.

Lucretius answers

It dissolves the fear, and it leaves the love of life standing. The two are easily confused, so let me part them. Begin with the soul, because the consolation is only a conclusion and the proofs come first. The mind falls sick with the body, is racked by dread of things to come, worn by care, stung by remorse when its sins are past, and plunged at times into frenzy and the dark waters of lethargy.¹

A thing that suffers so is no immortal guest lodged in a mortal house; to link the mortal with the everlasting is folly, for what is more at variance than that?² Therefore death is naught to us, since the nature of the mind is a mortal possession.¹ Then the mirror. When the Carthaginians came together in battle and the whole world shuddered beneath the coasts of heaven, in doubt to whom all power by land and sea must fall, we felt no ill, for we were not there.¹

So it will be when body and soul are parted: nothing can befall us who will not be. Even if time should gather our substance again and give us back the light of life, it would not touch us, once the remembrance of our former selves was snapped in two.¹ For if grief is to come to a man, he must himself exist at that hour for the ill to befall; death forestalls this and prevents the being of him on whom the misfortune might fall.³

The man who will not be wretched cannot be wretched, and it is no different from never having been born.³ The error lies in the man who mourns his own burning or mangling. He has left a part of himself standing by to feel it. He does not cast himself root and branch out of life, but all unwitting supposes something of him to live on, and so he pities himself, and from his own feeling taints the outcast body.³

In real death there will be no second self to live and mourn the loss.³ The mourners at the pyre say that one malignant day has taken all the prizes of life, and they never add that no yearning for these things abides with the dead man any longer.³ Does this argue against the love of life? Hear what Nature says when she lifts her voice. If the life that is past has been pleasant, and its blessings have not run through a vessel full of holes unenjoyed, why not retire like a guest sated with the banquet of life, and take with a calm mind a rest that knows no care?⁴

That is no contempt for the feast; it is the highest praise of it, that a man may rise from it filled. But if all has been wasted and life is a stumbling-block, why seek to add more, only to lose it again unenjoyed? Nothing more can be devised to please you; all things are as they were, even if you outlive all generations, nay, if you should never die.⁴

What I deny is that a longer stay would be a better one. I do not deny that the stay is sweet. And I have shown where the real torment lies. The pains told of in the depths of Acheron are in our life. Tantalus is the fool in vain terror of the gods and of the blow chance may deal; Tityos is the man torn by love and by care; Sisyphus is he who seeks power from the people, a thing that is but a name, and ever rolls back the stone; the maidens pouring water into the leaking vessel are the ungrateful mind that can never be filled.⁵

The fear of punishment after death is the conscience goading itself, and here on earth the life of fools becomes a hell.⁵ The poem argues against that life, the life of dread and of grasping. Against the life of a man who has looked at the world and enjoyed it, the poem says not a word, and Nature's own speech holds that life up as the model of one who departs content.

The position in brief

The soul is a body of fine particles, born with the body, grown with it, sick with it, and scattered when it is; the proofs are many and they come from what we see.⁶ Death therefore is naught to us: where death is, we are not, and the time after us is as the time of old before we were born, when the Carthaginians came to battle and we felt nothing of it; the nature of the mind is but a mortal possession.⁷

The man who imagines his own body mourned, or burned on the pyre, or torn by beasts, has left a part of himself standing by to feel it; that is the error. Acheron is here: Tantalus is the fear of the gods, Sisyphus the man who seeks office, the Danaids the ungrateful mind.⁸ Nature says: why not depart like a guest filled with life; and however many ages a man lives, eternal death will await him none the less.⁹¹⁰

Sources

Death, then, is naught to us, nor does it concern us a whit, inasmuch as the nature of the mind is but a mortal possession. And even as in the time gone by we felt no ill, when the Poeni came from all sides to the shock of battle
On the Nature of Things, pp. 134–135
to link the mortal with the everlasting, and to think that they can feel together and act one upon the other, is but foolishness.
On the Nature of Things, pp. 133–134
For, if by chance there is to be grief and pain for a man, he must needs himself too exist at that time, that ill may befall him. Since death forestalls this, and prevents the being of him, on whom these misfortunes might crowd, we may know that we have naught to fear in death
On the Nature of Things, pp. 135–136
why dost thou not retire like a guest sated with the banquet of life, and with calm mind embrace, thou fool, a rest that knows no care?
On the Nature of Things, pp. 137–138
Yea, we may be sure, all those things, of which stories tell us in the depths of Acheron, are in our life.
On the Nature of Things, pp. 139–140
So surely does one thing follow on another, nor is flame wont to be born of flowing streams, nor cold to be conceived in fire. Moreover, if the nature of the soul is immortal and Book ILI, ll. 625-655 127 can feel when sundered from our body, we must, I _trow, suppose it endowed 1 with { five s senses. Nor in any other way can we picture to ourselves" the souls wandering i 1N the lower world of Acheron.
On the Nature of Things, pp. 127–128
There is too the peculiar frenzy of the mind and forgetfulness of the past, yes, and it is plunged into the dark waters of lethargy. Death, then, is naught to us," nor does it concern us a whit, inasmuch as the nature of the mind i is but a mortal possession.
On the Nature of Things, pp. 134–135
These ahaa nature holds up to us as a mirror of the time that is to come, when we are dead and gone. Is there aught that looks terrible in this, aught that seems gloomy? Is it not a calmer rest than any sleep? Yea, we may be sure, all those things, of which stories tell us in the depths of Acheron, are in our life. Neither does wretched Tantalus fear the great rock that hangs Book III, ll.
On the Nature of Things, pp. 139–140
In such a compact are soul and mind ever bound together. Come now, that you may be able to learn that the 120 Book III, Ul. 417-446 minds and the light souls ® of living things have birth and death, I will hasten to set forth verses long sought out and found with glad effort, worthy to guide your life.
On the Nature of Things, pp. 120–121
Moreover, you see that our mind suffers along with the body, and shares its feelings together inthe body. If the shuddering shock of a weapon, driven within and laying bare bones and sinews, does not reach the life, yet faintness follows, and a pleasant swooning to the ground, and a turmoil of mind which comes to pass on the ground, 112 Book Ill, ll.
On the Nature of Things, pp. 112–113

Where the argument is made

Book III.417-829, the proofs that the soul is born and dies with the body
III.830-1094, "Death, then, is naught to us, nor does it concern us a whit, inasmuch as the nature of the mind is but a mortal possession," the mirror of the time before our birth, the man who pities himself as a corpse, the punishments of the underworld as the pains of this life, Nature's speech to the complaining old man, the banquet of life
I.112-126 on the soul's fate as the question the poem must settle

How the argument was received

The central doctrine of the poem and the one most argued against, from Plutarch to the deprivation accounts of modern philosophy; the texts are explicit and the fervour of them is Lucretius's own.