Reppert , Physicalism, Logica Docens et Utens
Victor Reppert writes:
A lot of the physicalist literature is guilty of one or
all of the following sins, which in my estimation are:
1) A dogmatic pre-commitment to materialism.
2) Changing the explanandum in order to make the physicalistic explanation possible.
3) Presuming the very ideas one is trying to explain naturalistically.
4) Issuing gigantic promissory notes to future science,
when we have no idea how future science will go.
To be honest, he [Richard Carrier] lost me when he said that laws of logic are procedures for finding the truth. That might be true of the principles of sound reasoning, but the laws of logic describe (as I understand it) the way things are, and we need to adopt principles of sound reasoning that take the reality described by the laws of logic into account.
BV: You may be alluding to the old distinction between logica docens and logica utens, logical theory versus applied logic. I think we will agree that logical theory forms a self-contained body of truths and a self-contained set of problems concerning consistency, completeness, etc. quite apart from any use to which logical theory is put in the governance of our actual reasoning. Logica utens is logic as normative, as issuing prescriptions and proscriptions as to our actual reasoning in pursuit of truth. It is grounded in logica docens. This is the position Edmund Husserl defends in the first two chapters of the Prolegomena to his Logical Investigations(1899), although he doesn't use this old Latin terminology.
The psychologism question arises when we ask about logica docens, logic as theory. Is it a part of psychology or not?
Is the Law of Non-Contradiction, for example, merely an empirical generalization codifying the factual inability of human beings to apply a predicate and its contrary to one and the same object at the same time and in the same respect? This is roughly the view of J. S. Mill. Husserl argues vigorously and persuasively against his and other psychologistic positions in the Prolegomena to the L.I. Husserl is required reading for anyone concerned with the question of psychologism in logic.
I may present some of Husserl's arguments later.