In lieu of an abstract, here is a brief excerpt of the content:The Happiness of “Those Who Lack the Use of Reason”Miguel J. RomeroHuman beings would have been created uselessly and in vain were they unable to attain happiness, as would be the case with anything that cannot attain its ultimate end.(De Malo, q. 5, a. 1, ad 1)A STUDY OF “those who lack the use of reason” in the thought and spirit of St. Thomas Aquinas has much to offer (...) the patient reader. We better understand what it means to be a rational animal, the image of triune God, when we investigate why, exactly, “mindless persons” (amentes) are not exceptions or even outliers in Aquinas’s account of the creaturely dignity and perfectibility of the human being.Aquinas remarks with some regularity on persons afflicted with the condition amentia, which is variously and inconsistently interpreted (in translation) as “imbeciles,” “fools,” “madmen,” “lunatics,” “the demented,” or “the insane.” The amentes are persons who lack the use of reason in a profound and debilitating way; and, as I will show, the fact that we are sometimes found in this state informs Aquinas’s analysis of human nature and, in particular, Aquinas’s teaching on the good wrought by Christ for the members of his body. Our guiding question is this: Thinking with Aquinas, how do we account for the natural and supernatural happiness of those of us who lack the use of reason?My purpose in this article is to explore what Aquinas has to say about the happiness of persons who are baptized and [End Page 49] confirmed by the Church, and who have what neuro-psychologists would describe as a profound cognitive impairment. The question is particularly striking when we recall that, for Aquinas, the distinguishing aptitude of the human being (proper to our intellectual nature and coordinate with our creaturely perfection) is the operation of an incorruptible intellectual capacity—a capacity, however, that is only reduced from potentiality to act when the corruptible “internal sense organ” is disposed to receive, in terms of health and circumstance, a coordinated sense impression of material species. Thus, a further question emerges: According to Aquinas, what is the perfective effect of grace in this life upon the nature of a person who completely lacks the use of reason due to an organic corruption or disorder of the ‘internal sense organ’?The discussion is divided into five parts. I begin (part I) by locating those who “lack the use of reason” within the theological infrastructure of Aquinas’s moral psychology and I identify the main problematic. With respect to that problematic, the principal conceptual resources provided by Aquinas are then outlined and two challenges are identified (part II).The first challenge is methodological, concerning the speculative import of the sacramental life of the Church. Francisco de Vitoria’s Relectio de eo ad quod tenetur homo veniens ad usum rationis (1534) highlights for us (part III) a constellation of judgments relevant to interpreting Aquinas on these themes, in particular, Aquinas’s formulation of prerational intellectual acts vis-à-vis the participation and membership of “mindless persons” in the sacramental life of the Body of Christ.The second challenge is to show the continuity between Aquinas’s account of the human being and his practical remarks on those who lack the use of reason. Specifically, given the various ways that, and degrees to which, the human being can lack the use of reason, I trace (part IV) Aquinas’s analysis of the power and operation of intellect, focusing on the intellectual acts which can be impaired and, concurrently, the intellectual acts which cannot be impaired in a living human being. Aquinas’s remarks on those latter acts not only reflect the [End Page 50] significance of the doctrine of the image of God in his account of human nature, but, even more, they shed light on the prosthesis of sacramental grace in his understanding of the properly human happiness capacitated and purposed in all whom God has called in Christ—a call to discipleship and devotion that includes those of us who have a profound, lifelong cognitive impairment (Rom 8:28; 9:11; Eph 1:3-14; II Tim 1:8-11).I conclude... (shrink)