ASEITY (Lat. aseitas, from a se “from itself, through itself”). — The property of a reality that does not derive its being from another. In Christian philosophy, a. is a perfection exclusive to God, underived and unparticipated Being, a se and per se. According to the doctrine of some Thomists, a. would further indicate the metaphysical nature of God: by the metaphysical nature of God being understood that fundamental note of the divine essence which, according to the human mode of knowing, is the primary root of the distinction between God and every created being, and the foundation of all His other attributes. According, however, to the more genuine Thomist thought, the prevailing doctrine places the metaphysical essence of God in the pure actuality of divine being “per se subsistens.” It is this infinity and per se character of divine being that grounds and explains, for us, His a.
Opposed to aseitas is, in Scholastic terminology, the term abafetas (ab alio “from another”).