I have learned that truth is what corresponds to reality based on the Correspondence Theory of Truth. but how do we use a theory to describe something that is absolute like truth? The Correspondence theory is not exactly a fact. Its a theory. How do we prove that the theory is true in and of itself?
@tabjohn0329 Great question It would obvious be circular reasoning to use the correspondence theory of truth to show that the correspondence theory of truth is true, so how can we test it?
I think what you would need to do is use a proof by contradiction. The way this works is that you assume that a proposition is false and then show that assuming the proposition to be false leads to a contradiction. It would work something like this for the correspondence theory of truth:
- because the correspondence theory of truth is false, it is valid to say that the sky is green
- that is a contradiction because we know that the sky, in the real world, is blue
- therefore, the correspondence theory of truth is correct
I suspect the actual proof would be quite a bit more complex, but that gives you the general idea.
In addition to the great points @SeanO made, I would point you to the idea of a “properly basic belief.” This is a belief that is so obvious that to question it would be to question all of reality. To deny a properly basic belief would be to veer off into radical skepticism. The idea that truth is that which corresponds to reality would fall into this category. Reality is true and that which is true will correspond to reality. There will not a mathematical proof for this, just as there is no mathematical proof that my hair is brown. Yet, we can know that it is brown through our experience. Perhaps this idea could be useful to you.
Thank you for the clarification Sean!
I would like to add to the above points.
There is really a lot we can’t prove.
It is difficult if not impossible to prove that we have reason or that we reason correctly at all in the first place. We could only attempt to use reason to prove reason is valid. This is not much of a proof of course. As noted above it is properly basic and we are left with a faith in reason.
There is another approach.
The inference to best explanation.
It seems reasonable that reason works in effect. As an inference that reason works seems reasonable then, but we can’t really prove it.
I do however like the idea that Jesus called himself Truth. There is an anchor to this idea of reason and logic based on an absolute truth found in God. If we were merely evolved as in mere naturalistic evolution (having nothing to do with a Creator) then it would seem strange and ridiculously unlikely to me that there could be any coherent thing such as reason or intelligibility. Why could we reason or relate at all to our environment at all? Even believing in the resurrection is mostly an inference to best explanation for the most part. It is mainly reason meeting revelation producing faith. Thomas Torrence had some good ideas on this.