Two problems with the last argument for the immortality of the soul in Plato’s Phaedo.
A problem with the argument as outlined in your handout is that C1 (souls must be alive
and cannot be dead) in fact does not follow logically from P1 (An organism has a soul if
and only if it is alive). Logicians call such a leap in reasoning a non sequitur. After all,
P1 is talking about organisms, not souls. In logical terms:
P1: For all organisms O, O has a soul if and only if O is alive.
C1: For all souls S, S is alive.
We could also modify the argument, so that it uses the concept of necessity. There are a
few ways to define “necessity.” One would be that a proposition is necessary if and only
if it’s the negation of a self-contradictory proposition. Another would be that a
proposition is necessary if and only if it must be true at all times, no matter what else is or
is not the case.
In logic, “it is necessary that…” is expressed by a box, “”.
This modified argument would thus go as follows:
P1: (Socrates has a soul if and only if Socrates is alive)
P2: Socrates has a soul. (Note that this is just a contingent fact; in other words, it’s
possible that Socrates might never have been born.)
C1: (Socrates is alive) – and thus Socrates cannot die. In other words, he is immortal.
This argument makes the same mistake as:
P1: (1+2=3)
P2: I have exactly 1 coin in my pocket and add exactly 2 more.
C1: (I have exactly 3 coins in my pocket)
The problem here is that the conclusion does not follow from the premises. Admittedly,
the proposition “I have exactly 3 coins in my pocket” does follow logically, but not C1,
which asserts that I must necessarily have exactly 3 coins in my pocket. After all, this is
just a contingent fact – in other words, it’s possible that I might have 4 coins in my
pocket.
Now admittedly, we could modify this argument as follows to make it valid:
P1: (Socrates has a soul if and only if Socrates is alive)
P2: (Socrates has a soul)
C1: (Socrates is alive) – and thus Socrates cannot die. In other words, he is immortal.
But this argument would commit the logical fallacy of begging the question, i.e.,
assuming the conclusion as a premise. For naturally anyone who believes that it’s
necessary that Socrates has a soul would also believe that it’s necessary that he’s alive.
Thus the argument fails to do what arguments are supposed to do: give someone who
doesn’t already believe the conclusion a good reason to believe it.
Interpretations of Socrates’ final words: “We ought to give a cock to Aesclepius.”
1. The translator’s interpretation, which is the “standard” one:
Socrates is certain that he has purified his personal soul so that it is completely free
from his body and its desires, and advises his friends to offer a sacrifice to Aesclepius
(the god of healing) in thanks for his personal soul’s being cured of the “disease” of
bodily life.
Problem with this interpretation: In fact, sacrifices appear to be made to Aesclepius
by sick people hoping for a cure, not (just) in thanks for having been cured.
2. A modified interpretation:
Socrates is certain that he has purified his personal soul so that it is completely free
from his body and its desires, and advises his friends to offer a sacrifice to Aesclepius
(the god of healing) in hopes that his personal soul will be cured of the “disease” of
bodily life.
Problem with this interpretation: If Socrates is certain that he has cured his personal
soul of the “disease” of life, then he doesn’t need Asclepius to cure him.
3. OK, one more interpretation:
Socrates is not certain that he has purified his personal soul so that it is completely
free from his body and its desires, and thus advises his friends to offer a sacrifice to
Aesclepius (the god of healing) in hopes that his personal soul will be cured of the
“disease” of bodily life.
Problem with this interpretation: Socrates’ theory (as presented by Plato in the
Phaedo) is that one’s personal soul is guaranteed to have been cured of the “disease”
of life if and only if one gains pure knowledge. And (for Plato, at least) knowledge
must be certain. Thus if Socrates isn’t certain that he has purified his personal soul,
then his personal soul cannot be cured of the “disease” of bodily life. Even
Aesclepius couldn’t help him out for this “disease”!
Conclusion: We must find an interpretation of Socrates’ last words that meets the
following criteria:
1. The sacrifice to Aesclepius is intended to get him to heal some kind of soul from
some kind of “disease.”
2. Socrates is thus uncertain that the kind of soul he’s concerned about will survive.
3. This kind of soul isn’t Socrates’ personal soul.
Argument:
Socrates in the Phaedo was either concerned with his personal immortality, i.e.,
the survival of his soul after his physical death; or he was concerned with something else.
Let’s assume that Socrates’ concern was with the immortality of his personal soul.
Now according to a view he espouses toward the beginning (cite), and then
toward the end of the Phaedo (cite), philosophy is a preparation for death. During his
natural life, that is, a philosopher tries to free himself as much as possible from the
distractions of his body, including importantly his senses, in order to better contemplate
the true objects of knowledge: the forms. To the extent to which a philosopher has
accomplished this goal, the philosopher has freed his separable soul from his body, thus
allowing it to survive the death of the body and live forever in contemplation of the
forms, never again to be reincarnated. (Note that the argument at the beginning of the
Phaedo assumes that genuine knowledge is possible, that it can’t be gained through the
bodily senses, and that it’s gained only by the soul’s attending to something else (the
forms). This doesn’t imply that the soul is immortal, but only that if genuine knowledge
is possible, then the soul is separated from the body for the time at which the soul has
genuine knowledge. The story told toward the end of the Phaedo is just that – a story –
and contains no argument.
Let’s now focus on the view – never actually argued for in the Phaedo – that the
genuine philosopher’s soul has secured immortality by gaining true knowledge of the
forms. (The ‘clothes’ argument, the ‘harmony’ argument, and the
If the argument is unsound, then Socrates has not successfully gained true
knowledge, but is instead deceived by his senses. That is, he makes a claim about a
relation between the forms of soulness, life, and indestructibility that does not in fact
hold. The correct relations seem to be that it’s necessary that if x has a soul then x is
alive. Furthermore (it’s necessary that) if it’s necessary that x is alive, then x is
indestructible. In this way, the form of soulness does not stand to the form of life in the
same way that the form of 3 stands to the form of numerical oddness. The problem here
is a category error: one can’t argue (without begging the question) that a person is a soul
(which would imply that the person is alive); rather,. This is quite different from: (the
Beatles) are a quintet; all quintets participate in the form of 4ness, and the form of 4ness
participates in the form of numerical evenness.
P1: Qb
P2: nec: (x)(Qx > 4x)
P3: nec: (x)(4x > Ex),
From which follows
C1: nec: (bQ > Ex)
And hence
Cs: Eb
In the case of the forms of soulness, life, and indestructibility, the argument would be:
P1: Ss
P2: nec: (x)(Sx > Lx)
P3: (x)(nec: Lx > Ix)
From which follows:
C1: Ls
But not
Is
This is because the argument fails to establish that it’s necessary that Ls
The confusion here can also be seen in the 2 premises: the first speaks of persons having
a soul; the second speaks of souls (but not persons) being alive. The second premise
should simply state that Sp = Lp. The subject of both propositions is a person, not a soul.
The form of soulness, that is, is a predicate, not a subject. If one considers the form of
soulness as a subject, then perhaps it would be correct to say that the form of soulness
falls under the form of life. But it’s no more necessary that Socrates has a soul than that
the Beatles are a quintet.
(Note that there are 2 problems here: the confusion (on the obvious construal of the
argument) of the subject in the first and second premises; and (on a different construal of
the argument) the slippage between a necessary conditional and a necessary consequent.
From which follows
C1: nec: (bQ > Ex)
And hence
Cs: Eb
pHs =def. Lp. But this definition doesn’t imply that Ls. Throughout the text, he does
give numerous hints that this is in fact the case (cite).