Tuesday, July 26, 2011

What is truth?

To: Marcus S.
From: Geoffrey Klempner
Subject: What is truth?
Date: 23 January 2004 13:38

Dear Marcus,

Thank you for your e-mail of 11 January, with your third Pathways essay, 'What is Truth?'

You offer 'Truth is an idea which is necessary for freedom' as a definition of truth.

This has something in common with a strong American tradition, known as pragmatism (principal exponents C.S. Pierce, John Dewey, William James). The fundamental idea is that belief is something we act on, and we have a strong prima facie reason to prefer beliefs the acting on which leads to success, over beliefs the acting on which leads to failure. Truth is a property of beliefs the acting on which leads to success.

This definition therefore implies that there is something that we *want*. It is only because we want things that we do things in the world, choose this over that, perform this action rather than that action. That does not go without saying. An intelligent machine might be thought of as an entity which has beliefs but no desires (I would argue that such an idea is in fact incoherent cf. the discussion of 'skyscrapers with arms and legs' in unit 5).

One obvious problem with your definition is that it is not, in fact, a definition. If you asked me for a definition of 'automobile' and I said 'an automobile is something which runs on wheels', you would then be entitled to ask me, 'Is anything which runs on wheels an automobile?' to which the answer is, No. Wheelbarrows run on wheels, bicycles run on wheels etc.

If truth is the *only* idea which is necessary for freedom, then you need to make the case for this. If truth is only one of the ideas which are necessary for freedom then you need to explain which one.

There is a case (as I have explained above) for saying that truth is somehow the most *fundamental* idea necessary for freedom. Without the possibility of truth of truth we could not act at all. Every action has a goal and presupposes the world being a certain way. If the world is a different way from the way we suppose, the action will fail.

However, there is an objection to the 'the truth is what makes you free'. Is it really true that the truth and only the truth makes you free? Suppose I believe that a particular class of human beings have no real feelings. I can do with them whatever I will. This makes me free to do things that I couldn't do before. The truth, that these individuals have real feelings and suffer like the rest of us, makes me less free.

Putting aside the formulation in terms of freedom, is it true, as the pragmatists seem to argue, that the success of an action 'proves' the truth of the belief which it depends on? Can't some false beliefs - like the belief 'My mother loved me', voiced by a son whose mother, in fact, hated and despised him - lead to success of one's projects, while the contrary belief leads to failure?

James appears to have thought that the truth of the belief in God could be justified on pragmatic grounds. That should raise alarm bells.

In response to my objection, the pragmatist might point out that false beliefs can succeed in the short run, but eventually if we continue to act on them the world will prove us wrong. The problem is that not all beliefs are capable of being 'proved wrong by the world' in this way, for example, the belief in God. Does that make the belief true, or does it show on the contrary that the truth or falsity of the belief cannot be assessed?

As you will have gathered, 'What is truth?' is not a matter for dictionary definition. It is a question which raises the deepest metaphysical issues. One way to consider the pragmatic view (I trust that you will accept my pigeonholing of your 'truth makes you free' formula) is by contrast with the views that it opposes. James rigorously opposed what he termed the 'intellectualist' view of truth, the idea that the truth is the truth whether we can ever know it or not, or whether or not it makes any possible difference to human life.

The correspondence theory of truth - a statement or belief is true if and only if it corresponds with the facts - is guilty of just such an intellectualist abstraction in James view because of the necessary assumption that facts are what they are whether we can ever know them or not.

You might recognize this as the issue of realism versus anti-realism discussed in unit 8. Pragmatism is an example of an 'anti-realist' theory of truth.

If asked to define truth, I would avoid a metaphysical answer. 'Is true' is the only predicate that can be substituted for X, without loss of truth value in all instances of the following formula:

'Snow is white' is X if and only if snow is white.

Put any sentence you can think of in place of 'snow is white', the result is always the same just in the one case where X=true. (Think of all the other things you can say about a sentence, that it is grammatical, poetic, has three words etc. etc. None of these can be substituted for X and still give the result we want.)

Of course, that does not dispense with the need to consider the metaphysics of truth - but that is another story!

All the best,