Key Arguments

• Socrates draws an analogy: ‘Supposing that the odd were imperishable, must not three be imperishable?’ and likewise, if ‘that which is cold were imperishable,’ snow attacked by heat ‘must not… have retired whole and unmelted’; similarly if the ‘uncooling or warm principle were imperishable,’ fire assailed by cold ‘would not have perished or have been extinguished, but would have gone away unaffected.’
• He formulates the parallel for the soul: ‘if the immortal is also imperishable, the soul when attacked by death cannot perish; for the preceding argument shows that the soul will not admit of death, or ever be dead, any more than three or the odd number will admit of the even, or fire or the heat in the fire, of the cold.’
• He acknowledges a possible objection—that although the odd will not become even, the odd might nonetheless ‘perish and the even take the place of the odd’—and notes that to answer conclusively one must assume ‘the odd principle is imperishable’; then one could say that, when the even approaches, ‘the odd principle and the number three took their departure.’
• Applying this to the soul, he says: ‘if the immortal is also imperishable, then the soul will be imperishable as well as immortal; but if not, some other proof of her imperishableness will have to be given.’
• Cebes replies that ‘No other proof is needed; for if the immortal, being eternal, is liable to perish, then nothing is imperishable,’ and Socrates adds that ‘all men will agree that God, and the essential form of life, and the immortal in general, will never perish,’ indeed ‘gods… as well as men’ agree that ‘the immortal is indestructible.’
• He then infers: ‘Seeing then that the immortal is indestructible, must not the soul, if she is immortal, be also imperishable?’ and Cebes assents; hence ‘when death attacks a man, the mortal portion of him may be supposed to die, but the immortal retires at the approach of death and is preserved safe and sound,’ leading Socrates to conclude that ‘beyond question, the soul is immortal and imperishable, and our souls will truly exist in another world!’

Source Quotes

Yes, abundantly proven, Socrates, he replied. Supposing that the odd were imperishable, must not three be imperishable? Of course.

Certainly, he said. And the same may be said of the immortal: if the immortal is also imperishable, the soul when attacked by death cannot perish; for the preceding argument shows that the soul will not admit of death, or ever be dead, any more than three or the odd number will admit of the even, or fire or the heat in the fire, of the cold. Yet a person may say: 'But although the odd will not become even at the approach of the even, why may not the odd perish and the even take the place of the odd?'

And the same may be said of the immortal: if the immortal is also imperishable, then the soul will be imperishable as well as immortal; but if not, some other proof of her imperishableness will have to be given. No other proof is needed, he said; for if the immortal, being eternal, is liable to perish, then nothing is imperishable. Yes, replied Socrates, and yet all men will agree that God, and the essential form of life, and the immortal in general, will never perish.

No other proof is needed, he said; for if the immortal, being eternal, is liable to perish, then nothing is imperishable. Yes, replied Socrates, and yet all men will agree that God, and the essential form of life, and the immortal in general, will never perish. Yes, all men, he said—that is true; and what is more, gods, if I am not mistaken, as well as men. Seeing then that the immortal is indestructible, must not the soul, if she is immortal, be also imperishable? Most certainly.

True. Then, Cebes, beyond question, the soul is immortal and imperishable, and our souls will truly exist in another world! I am convinced, Socrates, said Cebes, and have nothing more to object; but if my friend Simmias, or any one else, has any further objection to make, he had better speak out, and not keep silence, since I do not know to what other season he can defer the discussion, if there is anything which he wants to say or to have said.

Key Concepts

• Supposing that the odd were imperishable, must not three be imperishable?
• And the same may be said of the immortal: if the immortal is also imperishable, the soul when attacked by death cannot perish; for the preceding argument shows that the soul will not admit of death, or ever be dead, any more than three or the odd number will admit of the even, or fire or the heat in the fire, of the cold.
• if the immortal, being eternal, is liable to perish, then nothing is imperishable.
• Yes, replied Socrates, and yet all men will agree that God, and the essential form of life, and the immortal in general, will never perish. Yes, all men, he said—that is true; and what is more, gods, if I am not mistaken, as well as men. Seeing then that the immortal is indestructible, must not the soul, if she is immortal, be also imperishable?
• Then, Cebes, beyond question, the soul is immortal and imperishable, and our souls will truly exist in another world!

Context

Building on the conclusion that the soul is immortal (cannot admit death), Socrates adds a further premise—that what is immortal is also imperishable—supported by shared human and divine agreement; this yields the strengthened conclusion that the soul not only survives death but cannot be destroyed, fully answering Cebes’ earlier ‘weaver and cloak’ worry.