Wednesday, June 02, 2010

Why truth is not a predicate

As I have argued below and elsewhere, the copula 'is', as in

(1) Tom is running

has a twofold function. The first is to join subject and predicate together into a single content that is expressible by the sentence. For example 'Tom's running' or 'that Tom runs'. The second - and this is something only a verb can do - is actually to express this content. Thus

(2) Tom's running is the case

or 'That Tom runs is a fact' or 'it is true that Tom runs'. Now as it happens the operator 'it is true' which we attach to the that-clause 'that Tom runs' or 'is the case' which we attach to 'Tom's running' also contains the verb 'is'. But this, I argue, is a grammatical accident. The 'is' in 'is the case' is mere filling. The operator 'is the case' is a unitary element of the sentence. It would be better expressed by a single verb 'isthecase' or 'itistrue'. If it is essentially complex, then of course it contains the verb 'is', and if it functions as a copula, then it will have the twofold function described above. 'the case' would be a predicate that we could attach to the subject 'Tom's running' to form the noun-phrase 'Tom's running being the case'. And we could further assert this to form a new sentence 'Tom's running being the case is the case' and so on ad infinitum.

This is obvious with 'is the case'. We are not tempted into supposing that 'the case' is a predicate that qualifies Tom's running in any way. It is less obvious with 'it is true'. It is more tempting to suppose that the noun-phrase 'that Tom is running' refers to some content, a thing, and that in forming 'that Tom is running is true' we are predicating 'truth' of this content. Bad things lie in that direction.

See also Maverick Philosopher for a different take on why truth is not a predicate


David Brightly said...

Carrying on here rather than hijacking BV's posts... I like your drift but BV will fight you all the way. I have a couple of questions.

(1) How does the explanation of 'is true' as a sentential operator work when the sentential content isn't exposed? I'm thinking of examples like 'Some sentence is true', 'Every sentence of the Bible is true', 'I swear my testimony is true', and so on. There seems to be an indispensability argument somewhere in here

(2) What are the 'bad things'? I believe you mentioned the Liar paradox?

(3) What do you make of the following idea? If 'that Tom runs' or 'Tom's running' is the name of something, what kind of thing is it? Saying 'that Tom runs istrue' is a bit like an existence claim. The object/event described by 'that Tom runs' exists/occurs. Is this heading back towards a correspondence theory?


Edward Ockham said...

Hi David. To (1), see my most recent post above, on deflationism. To (2), I am going to post on this at some point. To (3), likewise. BV has already tackled me on this, rightly sensing a contradiction between my nominalism, and the positing of entities named by 'that' clauses.