Saint Thomas Aquinas and philosophical psychology

on the method of investigation of the first principle of life

Abstract

Among the many fields that the work of Saint Thomas extended beyond the theological sphere, one of them concerns the question of the division of sciences and the investigative procedures employed. From this perspective, we are interested in this work in analyzing the method that he considered appropriate in the investigation of the anima and, consequently, in the philosophical psychology that he formulated. Initially, the intended path will consist in the disposition of the methodological problem from the broader point of view of its context, that is, from the primary discussion of the classification of Speculatives Sciences, as present in Commentary on Boethius' Treatise on the Trinity. The observations of this juvenile booklet will be assimilated to those of Commentary on Aristotle’s de Anima, where we will have the specification of the reasons that establish philosophical psychology in the field of Natural Science. In continuation, we will deal with the theme of epistemic certainty and mode of demonstration that belongs to philosophical psychology; highlighting, therefore, that St. Thomas's formulation shows a full awareness that the direct inaccessibility of the object must be elucidated by a methodology that, starting from the effects, manifestations and properties, is capable of inferring the causes and substance of the first principle of life.