Abstract

This dissertation, consisting of three hundred and eighty-four pages of text, with multiple citations of the works of Heidegger and Aquinas, and of one hundred and ten pages of notes and bibliography, compares the phenomenological Seinsdenken of Heidegger with the metaphysics of esse of Aquinas. The perspective is Thomistic; however, the greater emphasis is on understanding Heideggerian Sein. ;Chapter I contains an extensive survey of the literature on the relationship between the two thinkers. Different commentators suggest various points of intersection between the two thinkers and disagree as to who is guilty of Seinsvergessenheit. ;Chapter II is a study of Heidegger's Seinsfrage which emphasizes the centrality of this question in the thinker's work, the phenomenological formulation of this question, and the limits of the thinking which the phenomenological formulation of this question predetermines. ;Chapter III contains a study of Heideggerian Sein in terms of: the Nothing, Truth, Presencing, Concealing, Clearing, Language, Thinking, Time, Ereignis-Austrag, and the Numinous. ;Chapter IV contains a review of those objects of Aquinas' thought to which the author believes Heideggerian Sein may be related: ipsum esse creatum, Ipsum Esse Subsistens, the transcendental Verum, the agent intellect, esse intentionale, esse as the verbal copula, and Ly Verbum. ;Chapter V contains the author's conclusions: Heideggerian Sein is in some respects like and in other respects unlike each of the objects of Aquinas' thought considered in Chapter IV. Sein is a conflation of really distinct principles which Aquinas is careful to distinguish, most fundamentally of esse reale and esse intentionale. Inasmuch as Aquinas can distinguish intentions from real things and can reason from the sensible beings which surround us up to a pure and real Being Itself he is more truly recollective of Being than is Heidegger