It doesn't prevent "truth" from existing. It simply prevents us from knowing as an absolute certainty that we've found it.
Yeah, that's what I was saying.
Let me give an example. My understanding is that we are quite certain that matter is composed of molecules, which are in turned composed of atoms. (Anyone feel free to correct me if I'm wrong in this, it's not exactly my field.) Now, if in fact this is actually the case, then we have discovered a truth. We consider this truth to be tentatively held, because we might discover something tomorrow that will change it all. But our considering it to be tentative doesn't prevent us from being correct if in fact we are.
Even if we are, in fact, absolutely correct, our tenativity prevents it from ever becomming "truth"
to us.
So we, ourselves, cannot have it as "truth" (even though it might actually be).
It might be "truth" in reality, but for us it will never be "truth".
Also, since we don't know what the "truth" is beforehand. How can we work
towards it? If we don't know what it is, how can we know we are going towards it? We can't. So all we can do is move away from what we do know is wrong.