To: Annabelle C.
From: Geoffrey Klempner
Subject: Hume's argument against the self/ soul
Date: 24th November 2009 12:52

Dear Annabelle,

Thank you for your email of 17 November, with your first essay for the Pathways Introduction to Philosophy program, 'Possible World Machine', in response to the question, 'The philosopher Hume remarked that when he looked into himself, he never succeeded in catching sight of his 'self', but only of particular thoughts, feelings and perceptions. Is that a valid argument against the idea of a soul?'

I gather from your essay that you believe in the existence of a non-material soul. As with many issues and questions that you will come up against in philosophy, the question whether a given argument for or against X is valid can be considered independently of whether you happen to believe in the existence, or non-existence of X, regardless of what X may be.

For example, an atheist and a theist can debate the question whether a particular argument for the existence of God, or a particular argument for the non-existence of God is valid. It is perfectly possible for the atheist to conclude that the argument for the non-existence of God is invalid, or for the theist to conclude that the argument for the existence of God is invalid.

I hope you're with me so far. Because this is about what it means to do philosophy, or what is involved in investigating a philosophical question.

Philosophers are interested in arguments, in the same way that doctors are interested in anatomy and biology. You can still cure people, but if you don't understand about human anatomy or biology then any medical cure you come up with is a lucky guess.

In a similar way, if your belief (in, say, free will, or the soul, or whatever) is just a belief, then it might be true or it might not. If it is true, then lucky you. However, what arguments enable you to do is discover the truth, sort out what would count as being in favour of the truth or falsity of a given belief.

You actually come up with a valid objection to Hume in the first line of your essay. This is really what the whole essay should have been about. Instead, you give various reasons for believing in the soul which have nothing to do with the argument which Hume gave.

Hume isn't just reporting on his own experience. He is issuing a challenge to anyone who believes in the existence of a soul: and first and foremost to Descartes, who in his Meditations gives the classic philosophical argument in favour of the existence of a non-material soul.

It was Descartes who claimed to be aware of his 'I' as a 'thinking, non-extended substance'. Was he reporting his experience, as he claims, or merely giving a theory to account for his experience? If he was just giving a theory, then the existence of the soul does not have the same 'indubitability' as the existence of my present feelings and experiences.

That's what Hume claims. If you are just stating what you know, based on your experience, then a 'self' or 'soul' is not given in experience. It's a theory or something you believe in order to explain or account for your experience.

Your objection -- which in fact was developed much further by the philosopher Immanuel Kant, in possibly the greatest philosophy book ever written, the 'Critique of Pure Reason' -- is that the very act of recognizing something, such as a momentary fragment of memory, a tickle, a smell, a sound, logically implies an 'I' which does the recognizing. Kant gave this the grand title, 'the transcendental unity of apperception'. Human consciousness is a logical unity, not just an accidental 'bundle' of experiences as Hume seems to imply.

However, as Kant went on to argue, you can't define the soul in terms of the 'unity of apperception'. To do so involves a logical fallacy. He put forward the following ingenious argument, very much in the spirit of Hume. Let's say that you are watching the clouds go by, or thinking about some philosophical problem, or meditating. You are aware that you exist now. The very next moment, you are aware that you exist now. The very next moment, you are aware that you exist now... You assume, or believe, that these awarenesses are produced by a soul or self which continues over time. However, *exactly the same experience* would arise if each momentary state existed only for that moment, and communicated its mental contents to the next like a line of colliding pool balls.

According to Kant, the truth, so far as the philosopher is able to ascertain, is that *we don't know* what the ultimate explanation for the unity of apperception, the 'I-feeling', is. Kant's view was that this is one of the questions which must be left to faith. It is beyond the range of philosophical proof or disproof. The aim of the philosopher, he said, is to 'set limits to the bounds of reason to make room for faith'.

All the best,

Geoffrey