Body and Soul in Ancient Philosophy

152
David Sedley
constructed along these lines, it is as powerful an argument for immortality
as Plato ever produced. Stage 1, in short, offers an impressive argument
for the impossibility of the soul’s dying, that is, for its being immortal.
Soul’s immortality lies directly in the impossibility of its coming
to admit the predicate ‘dead’, and does not depend on some further inference
added in Stage 2 for which that impossibility merely served as a
premise.
This brings me to my key question, what kind of immortality is
being attributed to the soul? If we had to turn to Stage 2 for an understanding
of this, we would have little to go on, since the argument for
imperishability that has traditionally been perceived in Stage 2 would be
a hopelessly imprecise one. But thanks to the immortality argument’s
relocation to Stage 1 alone, what we have arrived at is a very clear conception
of what the soul’s immortality consists in. For the soul to die is
not a practical but a logical or a metaphysical impossibility, of the same
order of impossibility as a cold fire or an even trio.
Which of these two labels is preferable? If we were to speak of ‘logical’
impossibility here, we should at any rate be careful not to think of
the impossibility that soul should die, fire become cold, etc. as simply
entailed by their definitions. No definition of either soul or any of
the other essential bearers appears to play any part in the dialogue’s argument.
9 Rather, the necessity that the soul be alive, confer life on whatever
it is in, and itself never admit death is presented by Socrates as having
an intimate relation to the “safe” causal efficacy which earlier, in his
Second Voyage (Phaedo 99d4 –102a3), he attributed to Forms. The
Form of Beauty, for example, is itself inalienably beautiful, and consequently
can only bring beauty, never ugliness, to whatever it affects.
Thus its predicative and causal attributes are ‘safe’ in the sense of
being altogether incontrovertible. The powers of the essential bearers
are introduced in the Last Argument explicitly as a more sophisticated
variation on this “safety” (105b5 –8). Hence any necessity or impossibility
governing those powers ought to be of the same kind as governs the
Forms. To call it a ‘metaphysical’ necessity would be a convenient way
of saying just that.
On the other hand, the reason why Forms themselves are incapable
of conferring their own opposites is ultimately to do with their status,
9 Contrast Laws 10, 895d1 – 896a4, where it is explicit that the name ‘soul’ represents
soul’s definition, which in turn conveys its essence; also Phaedrus
245e2 – 6, where self-motion is soul’s oqs_a, k|cor and v}sir.