I think that what i'm saying is: 1-that, if we would use Gibrans analogy of the box and the marbles, as long as there is no way of knowing the true state of the inside of the box, so if we would consider the box as a closed system, every statement about it's content has the same 'truth value', so they could be treated as logically equivalent. Yet, there has to be a box. Any statement that denies the existence of the box itself, cannot be true.
2-But there's another way of looking at the problem.
There is this ancient philosophical problem. The sentence "this sentence is false"...is it true of false? Well, if it's true, then it is false. But if it would be false, it would therefore have to be true...
So for ages, people have been trying to solve it. Some people have tried to solve it by disqualifying sentences that refer to themselves as a meaningfull sentence. The problem is that self-reference is just too common to do that. As a child we often use the self-referential aspect of language as a way to learn a language, for instance.
Another way would be to leave 'two-valued logic' where a sentence is either true or false. There could be another value, like 'neither true nor false' for instance.
But the thing is that "this sentence is either false, or neither true nor false", is essentially the same problem. If it is true, then it is false, and if it is false, then it has to be true.
There is another solution though, wich is also three-valued. It is called paraconsistent logic: Why not assume that something can BOTH be true and false? Ofcourse this aproach creates a lot of logical problems of itself. But we could solve many of those problems by for instance, considering cases like self-reference, to be special cases where two-valued logic does not apply.
So my second point is: maybe there are ways to deal with contradictory views, where they can BOTH be considered to be true.
But if we where to say that from there on, every view is just as valid as another, then you create a problem that is often refered to as 'explosion'. If everything goes, then EVERYTHING goes. Especially in logic, this is a problem. In normal, two-valued logic, anything can follow from a contradiction, for instance. So once you start to accept contradictions without any restrictions, you could eventually say something like: "because the sun is a planet as well as not a planet, fish are excellent cyclists".
So you need some kind of system to deal with contradictions.
I think that the notion of parallel reality's (or simmilar formulation), of wich one is a closed system, could be such a way. Or at least, it could be so, within the context of the debate on the truth of DMT-experiences.