I have been thinking about truth quite a lot recently. "Isn't that what philosophers are supposed to do?" Not really.
I guess I have been a card carrying Pragmatist for some time now, and as such I am usually pretty reluctant to make a big philosophical deal out of truth itself. I am more interested in what we might call 'truth markers' - evidence, justification, the social conditions for generating truth, on so on. Besides, most philosophical talk of truth is either banal (it reduces to 'truisms') or infected by the nasty bug of realist metaphysics (more about that on another occasion).
However - and, there is nearly always one of those - Pragmatists are also fallibilists. They are practised in the art of holding firm to the truth of something while keeping aware that it could turn out to be false. Since I know my views could be mistaken, I like to test them now and then by, as Nietzsche puts it, "thinking against myself".
So I have been doing a lot of metaphorical head-scratching lately: "Have I got it all wrong about truth?"
Then this line of argument popped into my head. I'm sure it's fallacious, but I can't yet see why.
And, it seems to cement my Pragmatist views even more firmly in place. No more head scratching for the time being.
Here's the argument (the brief version): "Truth/true" have no philosophical synonyms. Suppose X is an appropriate synonym, then 'Theory of X' will do all the philosophical work of 'Theory of Truth'.
But, after centuries of effort, nobody has been able to come up with an X that fits this bill. Now, since language is not like mathematics, it is highly unlikely that there is such a synonym - it's not that language is opaque in the way that mathematics can be (so there is no word that would do the job, hiding somewhere on the far shores of language or deep in the pages of some huge dictionary). But, we needn't go into this (it could trap us in the thickets of realism again). We can simply say that for working purposes, there is no known synonym. If there is no synonym for it, the word "truth" is not very informative (we know what to do with it, it serves a social function, but it doesn't 'say' anything directly -anything than can be substituted for it).
But, it seems to then follow that it is impossible to believe something simply because it is true.
Suppose I say to you "You should be believe P" and when you ask why, I say "Because it is true" - then you start behaving exactly as if you believe P.
What is going on? Can you have come to believe P solely because it is true? Surely not. Since "true" has no synonym, I might as well have said "Believe it because K" without telling you what K stands for. Your coming to believe P must have involved something else: either your belief that when I say something is true it is usually true (as when you value my opinion of wine and I say that the 1995 merlot is a good wine) or something in the content of P that links up with something else, say evidence, that leads you to believe P.
For Pragmatists, truth is like a stamp of approval - not that interesting in itself. The important philosophical issues surround the circumstances in which it is awarded correctly, and the implications thereof.