The method is termed the Inclusive Logistic Progression. Models that are elements of the progression are not judged as to truth or falsity but whether they are more useful or less useful for the particular job at hand. One model is not correct ipso facto thereby making a competing model incorrect. Models do not define reality but are tools that help us to make sense out of the world around us. They help us to make predictions.
Formal logic is simply an included subset within the much larger progression.
A predicate to this concept is Goedel's Incompleteness Theorem. In a credit economy there is no inherent need for a spread between interest paid on deposits and interest collected from borrowers because in such an economy loans are not made from deposits but are created ex nihilo as contracts. Deposits in a form of credit not created by the bank itself are needed only as reserves against the contingency that payment is demanded for some of the banks own credit instruments. In principle the interest charged on loans could be several times less than the interest paid on deposits. The bank could still make a profit.