[Eddier1]

You wrote:

"Any truth that one affirms presupposes, then, this deep truth: “the truth is the truth”. And that, far from being a tautology, indicates us that the truth can exist by itself, that is to say, without real concern, or ideal.

NB: By "first and last truth" I mean a primordial truth that presupposes every single one, and that is itself presupposed by all of them. I'm not thinking in a circle, but in a common trunk with infinite ramifications."

It is a tautology, nevertheless. It refers to the results of the Principle of Identity which only has validity in the realm of logic. And therefore tautology which is a logical form can invalidate your claim that "truth can exist by itself".

Logical forms do not exist by themselves. They are not entities in the empirical or material world. They are merely forms of thought, and as such can only function metaphysically.

As to your second NB, you are committing more than a logical fallacy by introducing infinite ramifications. You are committing a metaphysical error by multiplying entities unnecessarily, especially about an infinite that can only be an entity if and when the astrophysicists can prove that the Universe is infinite, and yet they have not been able to do that.

In math, it is only a game to use the nth degree in calculations, for example in calculating logrithims. And the biggest metaphysical error you commit of all is when you introduce the word "God" tacking it on to your logical argumentation for infinite ramifications and a cause which is a first cause necessary and sufficient unto itself.

No such first cause has ever been discovered, not even the "big bang" hypothesis claims to be a first cause. It is only a theory as to what happened. The elements in the primordial soup could well have always existed, and never were created at all. The entire Universe may be merely a fluctuation of the quanta found in the primordial soup. In short, what you see is what you get. And there is no need to multiply entities unnecessarily as Occam's razor suggests and which destroyed all the metaphysical errors of the Scholastics and all their logic chopping, which you also do exhaustively.