logic as objective performance and manifest capability of human beings,
You keep quoting these words of yours as though they were scripture, and treating the others as heretics for straying from them. Of course without ever explaining them. So I will ask specifically: Is
logic as objective performance and manifest capability of human beings different from (part of) what cognitive psychologists study under the umbrella of studying human reasoning? Is so how?
Yes, it's different. The term "human reasoning" itself says it all. Usually, these people will look at how language is used to produce arguments in a broad sense. Not my concern here. Deduction is never considered essential. Some authors even express doubts at to whether deduction plays any role. Deduction, if they talk about it at all, is taken to be properly modelled by mathematical logic, and this without even looking at any empirical evidence. They defer to mathematicians.
The scientific investigation of deduction as a capability is a minor aspect of the cognitive sciences and a fairly recent one. It is also limited to investigating how well human subjects perform at tasks of formal logic, which is not my concern here. They have no interest or motivation to develop any formal model of deductive logic based on empirical evidence.
Any formal model of deductive logic these scientists may need will be the one developed in mathematical logic, essentially because there is no other and perhaps cognitive scientists are deterred by the mammouth task of understanding the whole of mathematical logic before thinking about the possibility of developing their own model.
And is there any evidence that this logic as objective performance and manifest capability of human beings which isn't already studied as part of human reasoning even exists?
2,500 years of Aristotelian logic. Aristotle, the Stoics, the Scholastic, the school of Port Royal, most thinkers from Descartes to Locke to Hume to Leibniz to Kant have expressed themselves about it, some to question its usefulness but none to question its existence.
And I certainly have plenty of empirical evidence from my own personal experience, most of it compelling.
If you don't think you personally have anything like a logical intuition, so be it, but even there I would suspect you probably don't know where to look. Most people suck at this.
What would a science of logic as objective performance and manifest capability of human beings that is not part of cognitive psychology look like? Can you formulate any hypothesis, even an absurd one, in its context?
I'll have to think about it. No doubt it would be a difficult task, as already evidenced by the fact that no one is doing it. But, merely having the idea that it should be done, and probably urgently, would certainly help focus the minds of our brightest scientists. Sorry, I'm not one, so I can't really help here.
investigation that would try to develop a formal model of logic which would be accurate and operational.
How would it achieve that?
They would have to start by making accurate observations about the performance of human beings, initially to verify that mathematical logic is crap. So they will have to develop their own model from scratch. Scientists have proved themselves rather good at that sort of task, in particular with QM and GR. Maybe the deductive capacity of the brain is more difficult to understand, but I really doubt that.
And if logic wasn't a performance of human beings and a capability of the human mind, how come we would even talk about it? How come even mathematicians would have thought a method of logic was necessary? Boole called it "the Laws of thought". Do you think logic really is nothing else but the formal logic developed by mathematicians? From what basis, if not the human mind and the performance of human beings like the mathematicians themselves, as Frege thought?
EB