Truth


Reading

Fodor, Psychosemantics, Chapter 13 in Lycan.

Lecture where this is primarily covered

Week 14: "Truth"

We have discussed what a belief is, and what language is, and we have always been bumping into meaning.

Now we need to look at truth.

THE CORRESPONDENCE THEORY OF TRUTH

We have been assuming a view of truth, of what truth is. We have been assuming what is called the correspondence theory of truth. It is I think a very intuitive account of what truth is.

It is the theory that truth is a property of propositions, and that a proposition has this property when it corresponds to a state of affairs in the world.

So on this view first a proposition that is true purports to represent a state of affairs. We are familiar with this. But second the proposition is true if and only if the state of affairs it purports to represent really obtains.

CLARIFICATION: WHAT IS A PROPOSITION?

I haven't said anything careful about what a proposition is. We seem to need the notion if only because different natural languages seem capable of expressing in many circumstances the same thing.

La plume de mon frere

and

My brother's pen

seem to be saying the same thing. We express this fact by saying they are both expressing the same 'proposition'.

CORRESPONDENCE THEORY: A PROBLEM

Are there any difficulties with the correspondence view of truth?

PAUSE

Try a write one down before you read on.

The general problem is this: what can be meant by 'corresponds with'?

One approach has been to try and make use of the notion of a picture The following formula has been suggested: a proposition 'corresponds' with a state of affairs when it pictures it.

So it might be held that 'the desk is in front of the seats' pictures through words and grammatical structure the possible location of a desk in the room.

But it is difficult to see how to understand a 'picture' theory in other cases.

Eg

1. 'If my brother were here, we could eat at the new cafe'.

(A counterfactual statement)

2. 'You should wash the cat at least twice a day'

(A normative statement.)

In both cases it's not just the picture version of the correspondence theory that seems unable to cope. The idea that in these cases the proposition 'corresponds' to something is not at all clear.

FODOR'S VERSION OF THE CORRESPONDENCE THEORY

Fodor uses the correspondence theory of truth in his paper Psychosemantics, which I return to in a spirit of masochism.

Fodor's picture is that we are organisms, produced by evolution. The main business of our sense organs and brain-processing power - our 'cognitive system' - is to keep our behaviour adapted to our surroundings.

For example, if a lion is approaching fast, it is the job of our sensory apparatus and our cognitive system to pick this up and instruct our musculature to take evasive action.

He suggests we go along with the idea broadly that it does this by setting up inside us symbols, symbols which represent states of affairs outside us.

If that approach is right, when a lion is approaching, somehow our cognitive system will set up in our brains a representation of that.

That is the general picture. But to get clear about the issue of 'truth', we have to backtrack.

How does a process in the brain get to stand for 'A lion is approaching'?

We can assume a sensory apparatus.

The cognitive system discriminates a situation - lion attacking - and a process in the brain is launched.

This neuronac22213e.htm" target=_blank>Saith the wise

Poser

  • What is the relation between logic and grammar?

To move to another page, click on a topic on the left

Thus the rules allowed you to generate sentences - and to go on generating sentences indefinitely. They constituted a 'generative grammar'.

But let me go back historically to see what view of language Chomsky and the cognitive revolution was rejecting.

CONCEPTION OF LANGUAGE PRIOR TO THE 'COGNITIVE REVOLUTION'

Chomsky identifies three key questions which a theory of language must address. They are:

1. What is knowledge of language?

2. How is language acquired?

3. How is language used?

Chomsky argues that until the 'cognitive revolution' there was an approach to understanding language of the following kind:

These questions, says Chomsky, were answered by the theorizing that ruled before the cognitive revolution like this:

1. What is knowledge of language?

Answer: it is a system of habits, dispositions and abilities.

2. How is language acquired?

Answer: by conditioning, training, habit-formation or 'general learning mechanisms' such as induction.

3. How is language used?

Answer: Language use is the exercise of an ability, like any skill; say, bicycle-riding. New form are produced and understood 'by analogy' to old ones. In fact, the problem posed by production of new forms, the normal situation of language use, was barely noticed. (This is a quite remarkable fact, first, because the point is obvious, and second, because it was a major preoccupation of the linguistics of the first cognitive revolution of the seventeenth century. Here we have a striking example of how ideology displaced the most obvious of phenomena from enquiry.)

Thus:

A key answer given by the conception of language that ruled before the 'cognitive revolution' implied that knowledge of language was knowledge of a skill.

This is the approach to language that you might find familiar.

('This answer, incidentally is still widely held, notably by philosophers influenced by Wittgenstein and Quine.' - Chomsky, in Lycan, p.638.)

REASONS FOR REJECTING THE 'PRE COGNITIVE REVOLUTION' UNDERSTANDING OF LANGUAGE.

Chomsky says the simplest of language phenomena are enough to show that this approach must be wrong.

ARGUMENTS AGAINST THE PRE-COGNITIVE REVOLUTION CONCEPTION OF LANGUAGE

He gives a number of exmplesof complicated grammatical constructions. His point is:

The great sophistication with which young children understand different grammatical constructions goes way beyond what could be learnt from making inductions from the sentences that the child directly encounters.

Innumerable complicated rules of grammar, he says, are known by children without training, or even experience.

'These facts are known without training, without correction of error, without relevant experience, and are known the same way by every speaker of English - and, in analagous constructions, other languages.'

(Chomsky, in Lycan, p.640.)

Considerations of this kind, says Chomsky, show the inadequacy of the conception of knowledge of language as a skill or ability. It is not the exercise of a skill when we interpret a sentence corrrectly. 'Rather, the computational system of the mind/brain is designed to force certain interpretations for linguistic expressions.' (Chomsky, in Lycan, p 640)

The approach to language that held sway before 'the cognitive revolution,' says Chomsky, was 'entirely unproductive and without empirical consequences'...One can hardly point to a single empirical result of the slightest significance that derived from these conceptions. The psychoge, click on a topic on the left