Abstract

This study, on Thomas Aquinas’ doctrine on the transcendentals, is both epistemological and metaphysical. From the epistemological point of view, we want to determine if and how the sequence subiectum / principia subiecti / passiones subiecti can be applied to ens qua ens and to the transcendentals. Our investigation concludes that the five transcendentals – res, unum, aliquid, verum, bonum – are effectively founded on the principles of ens, and that the last four are counted among the properties that are predicated per se secundo of ens, even though they do not add anything real to their subject, but rather only a negation or a relation of reason. From the metaphysical perspective, we want to clarify, in the most precise way possible, the additio rationis proper to each transcendental, and then explore the nexus that links each of them to the esse of ens. What results is that the transcendentals are ultimately founded on the act of being that is the terminus of the metaphysical resolutio, and that each transcendental explicates an aspect of esse considered as perfectio omnium perfectionum.