Earlier quoted context omitted.
I believe there is only one truth, and everything else is false. But I also believe humans do not have access to it.
I agree with this position. The idea that there may be 'truths' sounds utterly bonkers to me. a ^ -a is considered a contradiction for a reason.
For example, one of the stunning consequences of Special Relativity is that there exist situations in which an observer says that event A happens before event B, and another observer says that event A happens after event B, and both are correct. Nature does not appear to be at all bothered by this "contradiction", however, and the world works just fine. Even more puzzling "contradictions" arise in quantum mechanics.
For all we know, it appears that reality is indeed dependent on the observer at a deep level. Maybe there is an even deeper level at which statements such as "a ^ ~a is false" hold, but so far nobody has been able to discover any.