Yes, without being able to say "for all practical purposes this is true" we'd be crippled.
Without being able to deny truth in safety we are not free... Look at the facts, which I have not even an imaginary handle on, of how many people have died for religious truth, or scientific truth, or political truth, or economic truth, or social truth; and you can see that truth is not the friend of humanity, but its enemy...Better a useful lie that keeps humanity safe than any number of truths that leave humanity is a mass grave...Better for everyone to have enough than for a few to light up the night in Auto de Fe's...The truth will be truth no matter what people think, but the truth is also a simple form of relationship, that like all relationships should keep all parties to it alive... As soon as the truth starts killing people, call it what you will, it is horrible...
---------- Post added 03-13-2010 at 07:35 AM ----------
Aristotle said that a statement is true if it says of what is that it is, and of what is not that it is not (Metaphysics Γ, iv. 1011).
Sounds right to me.
You have got to move beyond such a simple conception of the thing, because the thing, truth, is not a thing at all, but a moral object, a spiritual conception that is meaning only, without being...Since not one of us can know truth, or define truth, since truth is an infinite; so we should not try in more than a cursury fashion to say what it is... This is more true than that, given that truth as an absolute can only be approached and never touched- is good enough.