ABSTRACT
EVERY psychological explanation comes sooner or later to lean either on biology or on logic (or on sociology, but this in turn leads to the same alternatives). For some writers mental phenomena become intelligible only when related to the organism. This view is of course inescapable when we study the elementary functions (perception, motor functions, etc.) in which intelligence originates. But we can hardly see neurology explaining why 2 and 2 make 4, or why the laws of deduction are forced on the mind of necessity. Thus arises the second tendency, which consists in regarding logical and mathematical relations as irreducible, and in making an analysis of the higher intellectual functions depend on an analysis of them. But it is questionable whether logic, regarded as something eluding the attempts of experimental psychology to explain it, can in its turn legitimately explain anything in psychological experience. Formal logic, or logistics, is simply the axiomatics of states of equilibrium of thought, and the positive science corresponding to this axiomatics is none other than the psychology of thought. With the tasks thus allotted, the psychology of intelligence must assuredly continue to take account of logistic discoveries, but these will never go so far as to dictate to psychology its own solutions; they will merely raise problems for it.
