I think SP's posts are contradictory. This understanding, in his view, isn't a science or a theory.We all have access to the same basic information. We all have the same kind of brain. The understanding that human beings have a deductive logic capability dates back at least to Aristotle.
Then we get this:
"the question" hasn't been answered since Aristotle, apparently, this is obvious and something we can all, erm, deduce for ourselves.All the major thinkers in the intervening time have pondered the question, with various perspectives, but they all have spent time on it and written on it. Mathematicians themselves in the 19th started out thinking in the terms I have outlined. The title Boole chose for his book starts with the words "The Laws of Thought". Frege also thought in terms of logic as a performance of human beings. He meant to develop a method of logic adapted for mathematics but one that would be a formalisation of the mathematicians' logical thought, and, presumably, mathematicians have the same basic logical capability as any other human being in good health. So, no, I don't buy that I needed to provide any detail.
So for some unspecified reason we can disqualify everything since Aristotle from being a science of logic. And we have to exclude Aristotle too because he didn't answer "the question".