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Plato's argument from opposites for existence of the soul


To: Scott B.
From: Geoffrey Klempner
Subject: Plato's argument from opposites for existence of the soul
Date: 9th December 2008 12:22

Dear Scott,

Thank you for your email of 27 November, with your essay in response to the University of London Plato and the Presocratics question, 'Discuss whichever you take to be the best of many arguments that Plato offers for the immortality of the soul.'

I concur with your worries expressed in your email: Is the argument from opposites really the best argument that Plato offers, in your opinion? If it isn't, then you should have chosen the argument that you think is the best.

If you get this kind of question in the exam, then you can assume that the examiner is looking for an explanation of what you think is good about the argument in question, or at least why you think it is better than the alternatives on offer.

Did Plato believe in reincarnation? That is a much discussed topic. I am not sure that he did, although he was prepared to look at arguments deriving from the Pythagoreans in order to assess their validity. In the Phaedo, Socrates tries various arguments, but the didactic purpose of the dialogue is to get you thinking about the problem of death and the fate of the soul and possible solutions, rather than simply to convince you of the truth of the doctrine of immortality (like a philosopher who takes the pragmatic attitude, 'If first argument doesn't work, you try the second, and if that doesn't work you try the third etc. etc.').

How good is the argument from opposites?

It is helpful to think of how the argument would work on the supposition of materialism. Things do not live forever. What comes alive, does so as a result of a process of transformation of materials which themselves not alive. How would you prove that? In fact, that claim is notoriously difficult to establish. For a long time, scientists believed in the doctrine of 'vitalism' according to which there is a unique life principle which characterizes certain kinds of entity, right down to the compounds studied in organic chemistry. The doctrine was only finally refuted by Buchler's experiment in the 19th century where the organic compound urea was synthesized from the inorganic compound ammonia.

According to the vitalist, in other words, 'life' or the 'vital principle' can only come from life. That example would be sufficient in itself to serve as a logical counterexample to Socrates' claim that 'things come from their opposites'.

However, perhaps there is still hope for Socrates here. Let's take it that *apparently* lifeless material is transformed into a living human body, while living human bodies die and are transformed into lifeless material.

The crucial 'lemma' here is a result which Socrates has already established: there is such a thing as the soul. We are assuming the falsity of materialism. A living human body is alive because it has a soul -- whatever the soul may be, a question which we still need to answer.

One possibility is indeed that when the body dies, the soul is 'dissipated'. A soul cannot exist without a body. However, it is legitimate to ask how that would be possible. We have established that a living body is made up of previously unliving matter, then is transformed into unliving matter once more. By analogy we might conclude that the soul is made of some kind of 'soul stuff', which although dissipated at death, is collected together again and transformed into a living soul once more.

In other words, there are two 'conservation principles' at work here: the conservation of matter -- no matter is annihilated, all material things come from previously existing material -- and the conservation of soul -- no soul stuff is annihilated, all souls come from previously existing soul stuff.

The problem with this theory is that I don't care if my soul is made from the material that once constituted some other soul. That isn't survival, any more than is the fact that my body is made of material which might have once constituted another body.

However, there is strong evidence from the Phaedo that in fact Plato would have rejected any 'soul stuff' theory had he considered it. A soul is not the kind of thing that can be 'dead' (by contrast with material bodies). It is essentially alive.

-- These are just ways in which you might explore the argument. What the examiner is looking for (to repeat) is evidence that you not only understand the argument in question, but also a demonstration of your ability to analyse an argument, spot its weak points, shore them up if necessary, assess the validity of the revised argument, and so on.

In doing this, you should give as little background information as necessary for conveying the argument in question. In your essay you spend far too much time talking about the context, or the issue of opposites in general. What is the argument? What does Socrates mean when he says...? Is the argument any good? How could it be made better? These are the kinds of question you need to answer.

All the best,