I'll stick with Plato, thanks. :loser:
For those of you who haven't read the
Phaedo, I'd like to clarify the above: the notion that the soul lives many lives comes from his earlier position in the
Meno. Plato has a problem of
a priori knowledge. If I know truths that I didn't learn in this life, where did I learn those truths?
How is it that the little slave boy of the
Meno can tell me that, in order to double the size of a square, that I must draw the sides of the double to be equivalent to the diagonal of the smaller? [Suppose I have a square with each of its sides measuring 3 meters. In order to draw a square exactly twice that size, each side of the new square must measure a number of meters equal to the square root of 18.]
Well, since the slave boy didn't learn it in this life, he must have learned it in a previous life. In the
Phaedo, Plato appeals to this notion in order to argue for the immortality of the soul. Since I know
a priori truths, then I must have existed prior to this life. Therefore, I'll continue existing once this life ends.
It should be noted, however, that the dialogue doesn't end there. That argument doesn't hold. His interlocutor asks: "Granted, you've lived prior lives. But why should you go on existing indefinitely? Maybe you've lived a number of lives, but this is your last one. Your time really is running out." Socrates answers that the soul, being a principle of life, cannot die, since death is the opposite of life.
So, there's two problems here:
1. Does the problem of
a priori knowledge indicate that we've lived previous lives?
2. Does the soul's being a principle of life ensure that it must always live?
The answer to 1 is an obvious "no." If the truth in question is
a priori, that is to say, a truth that I cannot learn through sense knowledge, then saying that I've lived previous lives doesn't help answer the question. It only pushes it back. How did I learn the truth in that previous life?
I think that it's ultimately this concern that led Plato to write the
Phaedrus. In that dialogue, Plato doesn't claim that we learn eternal verities from previous lives. Plato says that we learned the eternal verities prior to this life when we saw them directly in a state of pre-existence in the intelligible world. We looked directly upon The Good.
So, when it's all said and done, does the notion of
a priori truth indicate that we have to believe in reincarnation? I don't even think that the Plato of the
Phaedrus thought that.
The answer to 2 also is a pretty obvious "no." Granted, insofar as the soul is a principle of life, insofar as it exists, it must live. But Plato has begged the question. What if the soul should cease to exist? Then it no longer will be a principle of life, and there is no reason that it should continue to live.
2 may be a good argument for some sort of universal animating principle, but certainly not for individual living things. We don't say that a blade of grass lives innumerable lives.