QuestionsShould we fear death?The soul survives: the argument from opposites
Should we fear death?The soul survives

The soul survives: the argument from opposites

Plato c. 428 BC · c. 348 BCBeyond appearances, the eternal Forms.
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What it claims

The souls of the dead exist somewhere, from which they come back to life.

Why

Everything comes from its opposite, as waking from sleep: the living come from the dead, so the soul must exist in between.

In short

"The soul survives: the argument from opposites" is an argument by Plato (Phaedo, 70c-72e) on the question "Should we fear death?" (answer: the soul survives). Its claim: The souls of the dead exist somewhere, from which they come back to life. According to AskPhilosophy's logic check (Z3 solver), the argument is valid only if one grants a premise the author leaves unstated (P3). AskPhilosophy presents 2 objections, 1 of them with a documented reply, and the original text behind each premise, checked word for word.

Phaedo, 70c-72e
Valid with an implicit premise

On the day of his death, Socrates wants to show his friends that the soul does not vanish. First argument: everything comes from its opposite, life as well as death.

P1Everything that has an opposite comes from its opposite: the larger from the smaller, waking from sleep.
P2Living and being dead are opposites: the dead come from the living, so the living come from the dead.
P3 · implicit premiseFor the living to "come back" from the dead, something must exist in the meantime: the soul.
Therefore the souls of the dead exist somewhere, from which they come back to life.

click a premise to reject it

If you accept every premise, logic forces you to accept the conclusion. So the debate is about the premises.
Checked by a logic solver: the premises cannot all be true while the conclusion is false.
Without the implicit premise: Without P3, the computer finds a case where the living do come from the dead without anything persisting in between.
Without P3, the cycle of opposites says nothing about the soul: one must assume the same thing passes from death to life. Socrates himself states it as a condition of his proof.
Analogy. If people wake up every morning, they must have been asleep: waking presupposes sleep, and sleep presupposes someone who sleeps. Plato applies this reasoning to life and death.

Objections

2

Each objection is a conversation: click to see who replies and where the debate stands.

S
Simmias and Cebes (in the dialogue) attacks the conclusion

You have proved half: that the soul existed before birth. But nothing prevents it, at death, from being dispersed like smoke and ceasing to exist.

Platon replies
Platon Socrates' reply (Plato's character)
Just combine the two proofs: if the soul exists before birth, and every living being is born from the dead, it must also exist after death in order to be born again.
Aristotle 350 BC · attacks premise 3

The soul is the form of the living body, like the shape of a statue: it cannot exist apart from it. Nothing "passes" from one life to another.

no reply
summary: their text is not yet in our corpus
We have not yet found a direct reply by Platon in the texts.