Abstract

The aims of this dissertation are to categorize, clarify, and assess Thomas' arguments for the immateriality of the intellect. ;The five principal texts are: Scriptum super Libros Sententiarum II, d.19, q.1, a.1; Summa Contra Gentiles II, Chapters 49 and 50; Summa Theologiae I, q.75, aa.2, 5; Quaestiones Disputatae De anima, a.14; and Compendium Theologiae, Chapters 79 and 84. ;Of the thirty-six arguments for the immateriality of the intellect surveyed, thirty of them can be collected under five basic types. Type 1 argues that since the intellect is in potency to know all sensible things it must not be composed of any sensible thing. Type 2--the intellect's grasp of the universal transcends the limits of matter and therefore it could not be composed of matter. Type 3--since knowing involves the unity of knower and known, impossible consequence follow if the intellect were material. Type 4--if the intellect were a material organ then it could not know itself as it does. Type 5--while contraries cannot exist together in a body, they do exist together in the intellect. ;Although some new arguments are introduced and others are dropped, types 1 and 2 remain the primary arguments throughout Thomas' career. Type 1 is preferred by Thomas, but it is actually type 2 that is most pervasive. The expression of type 2 varies more than that of type 1; type 2 is often combined with elements of other arguments, an indication of its fundamental character among these arguments. I argue that type 2 is the most fundamental argument for the immateriality of the intellect, and is most promising for use in the present day. ;Type 1 is an incomplete rendering of Aristotle and is inconsistent with Thomas' own description of the internal sense powers. Insofar as one fortifies type 1 by pointing to the different way the intellect has its object , one is actually using type 2 to maintain type 1. Furthermore, type 1 does not allow a proper assimilation of modern findings about brain function, and finally, it does a disservice to the unity of the person