Truth is not a property of ideas. Truth is a relation between an idea and the world and while it depends as such on the idea in question it does not depend on the mind having the idea for a given idea. Somes ideas may be problematic in this context but not any idea which is not about the mind or part of it.Absolute truth is an oxymoron. Absolutes are what they are independent of sentient minds, but truth is a property of ideas, which can only come from sentient minds.
Hmmm.. Mathematical truths may have no relationship with the real world, and indeed may be impossible to instantiate, and yet still be true. As such, I don't agree that truth is a relation between the idea and the world.
"Absolute truth" is not an oxymoron. It is just that truth is necessarily absolute (so "absolute" is redundant). To talk of absolute truth is therefore to suggest there are truths which are not absolute, and that is idiotic.
EB
1) Superman wears a blue cape
2) Superman wears a red cape
You saying that both of these statements have the same truth value? Are you saying that either of these statements is absolutely true?
If absolute truth is something that is true in all contexts, and we have contexts in which statements can be true (the fictional character superman does indeed wear a red cape) and in which they can be false (there is no real superman, who wears a red cape), then it seems clear that truth is entirely dependent on context, and isn't absolute in the slightest.