Phaedo Immortality of the Soul
Powerful elements amongst older generation of Athenians, however, tended to find cause to view Socrates' teachings to be corrupting or sacrilegious. Such condemnations led to Socrates being sentenced to effectively "take his own life" by imbibing a draught into which a lethally poisonous amount of Hemlock had been included.
When this sentence was imposed Socrates was about seventy years of age, and, although some of his friends offered to arrange for his going into exile as an alternative, he opted to comply with the sentence-of-death which Athenian authorities had delivered on him.
In Plato's work Phaedo reports are included in which several of Socrates' reasons for this compliance are set out.
Socrates explains to his friends that a true philosopher should look forward to death. The purpose of the philosophical life is to free the soul from the needs of the body. Since the moment of death is the final separation of soul and body, a philosopher should see it as the realization of his aim. Unlike the body, the soul is immortal, so it will survive death.
Socrates provides four arguments for believing the soul is immortal.
The first is known as the Argument from Opposites
"Let us consider whether it is a necessary law that everything which has an opposite is generated from that opposite and no other source."
Phaedo
Since life appears to have death as its opposite a case is made that life must come from death.
Phaedo
The second argument is known as the Theory of Recollection
"what we call learning is really just recollection. If that is true, then surely what we recollect now we must have learned at some
time before; which is impossible unless our souls existed somewhere before they entered this human shape. So in that way too it
seems likely that the soul is immortal."
Phaedo
As the soul must have existed prior to birth to acquire certain knowledge there are grounds for accepting that the soul's life is not
the same as that of the body.
Phaedo
The third argument known as the Simplicity Argument or the Argument from Affinity
Souls are held to be immaterial and imperishable whilst the body is held to be material and perishable.
Socrates' fourth argument is based on the Theory of Forms.
A Form, (of which there are held to be many), is perfectly true to itself.
We are alive because we have souls, implying a direct linkage between soul and the "Form" of life. The "Form" of Life is held to be free from any trace of death this further implies that souls must be immortal.
Several truly notable authorities
endorse Tripartite Soul Theory
Key Socratic Dialogues from
Book 4 and Book 9 of Plato's Republic
Plato's Ideal State Plato's Chariot allegory
Philosophy - Eastern and Western & 'Tripartite' Human Nature
FIVE major World Religions & 'Tripartite' Human Nature