Is the statement "Claims demand evidence" always true?

[Mudhammam]

The trick, at least to me, is to understand that absolute reality and reality-in-context don't have to be the same thing.  In the context of mundane life, I can say that there's really and truly a book on my desk.  I know that if anyone else comes into my room, they will agree with me that there is in fact a book on my desk.  However, in a more universal context, I cannot be sure that the book, the person, and maybe even I, exist objectively.  It is the given that things are real that establishes the context for truth and objectivity.

The problem is that metaphysical positions SET the context by which other truths are determined, so when we attempt to establish the truth of a metaphysical position, the truth statement will be either self-dependent, or automatically-defeated, or complete nonsense.

(bold mine)
To me that's probably the least trivial fact one can recognize because we don't decide which 'truth statements' will have such and such features.  That's why I have some sympathy with those who argued for something like Divine Reason, which, for me is just a poetic way of saying that our "mental coherence" forms its reality-in-context of absolute reality.