But what you wrote about "denying logic" does not seem to have anything to do what R. said about truth. I am not a mind-reader. How could I tell that from what you wrote?

5. Is much of what is called logic founded on questionable axioms? For instance, should we consider Hegel's criticism of the Law of Excluded Middle?

Im not pretending that i was very clear

I was contending Reconstructo's interpretation of logic, i wanted him to clarify the impact of persuasion on truth, and his idea that there is no absolute reality in a world of change. That is how i interpreted his post and mine was a response to it. I saw him as subordinating logic to whim and subjectivity. I however, believe there is a reality completely independent of humanity, and there will be after we are gone. This may be a diversion from the original topic, but is not irrelevant, since metaphysics is the fundamental premise for any argument.

so what is at issue is not logic as such but its range of applicability. I suppose in traditional logic there was a belief that such laws as the law of the excluded middle applied in all times, places and situations, whereas subsequently it has been shown that this is not the case.

It's not so much particular cases but types of cases. I would think (and am no expert here) that there are types of situations to which the rules of classical logic can be applied very successfully - many such cases, in fact. I suppose, speaking intuitively, these are where the essential facts can be discerned, and the connection between the premisses and the conclusions reasonably ascertained.

But I think what has happened as society and knowledge have developed, is that we now often confronted with very complex, fluid, or chaotic situations, whether these be scientific, political, economic, or whatever. Market dynamics, or the way epidemics behave, or chaotic systems, often would seem to throw up problems that are not amenable to strictly logical analysis.

Also I think that Aristotlean logic in particular, and the laws of identity and the excluded middle and so on, really don't cope very well with 'the new physics' which is in fact one of the reasons that people are casting about for other logical and metaphysical systems within which they can be interpreted.

That is what I had in mind. I am just improvising here and anyone with more training in logic and so on may know a great deal more.

Everything depends on the argument for the inapplicability of the rule to the particular case. I don't want to be dogmatic about the matter. There might be reasons to restrict the scope of some of the laws of logic. But it would depend. I think we should be reluctant to do so unless there is a compelling reason to do so.

You should extend the same courtesy to the law of non-contradiction.

Everything depends on the argument for the inapplicability of the rule to the particular case. I don't want to be dogmatic about the matter. There might be reasons to restrict the scope of some of the laws of logic. But it would depend. I think we should be reluctant to do so unless there is a compelling reason to do so.

Theory of computation/recursion is based heavily on intuitionist logic/contructivist mathematics, that is, they are based on first order logic without the law of excluded middle (and infact, with bounded quantification). Also, quantum logics and fuzzy logics require different rule sets to achieve certain ends. Fuzzy logics need to allow for gradated set inclusion because it takes sets of 'red' objects or 'thick' objects into account, these status types occur practically in a continuum so truth values range from [0,1] on the real number line.

The logic with which you manipulate your data or axioms needs to reflect the behavior of the objects you are considering. This is why quantum logic is needed. In reality, logic is quite a bit like mathematics.

What would any of you describe logic to be founded upon in the first place? Is logic founded upon logic? Is logic founded upon tautology? I haven't studied logic's self-justification so the question is asked in earnest?

Side note: antecedent skepticism: is it refuted by anything other than "common sense," than the fact that man cannot afford it? That it must be an insincere viewpoint for man as he is constituted?

Something that scientists often fail to realise, in my view, and more so in the current 'scientific age', is exactly that logic and mathematical reasoning don't go 'all the way down'. They rest on assumptions and axioms at some point, beyond which they cannot be applied. As for the logical foundations of math, isn't this what Russell and Whitehead tried to establish, and Godel showed couldn't be done? I think logic is very much a tautological system. But skepticism is something that needs to be understood and applied correctly. In my view, scientific skepticism is pseudo-skeptical, because it is all predicated on the type of naive realism which is the first thing that the real skeptic calls into question.

Hegel, for all his faults, tried to give the world a Science that would go all the way down. But I don't think he attained "absolute knowledge." I think "the impossibility of closure" is a more likely scenario. Of course we experience moments of transcendence and peace. And this is a passing closure.