An examination of Aquinas's approach to conscience

Aaron William Converse, Fordham University


The main purpose of this dissertation was to provide a close examination of Aquinas's analysis of conscience. As such, it involved three broad aspects. First, I give a historical analysis of the writings on this subject. This includes a brief examination of some of the writings that influenced Aquinas (including the commentary of Jerome on the Book of Ezekiel and also the Summa Halesiana), as well as a comparison of Aquinas's earlier writings (from De Vertitate and his Commentary on the Sentences ) with his more mature work (from the Summa Theologiae). I argue that there are certain broad similarities between Aquinas's earlier work and that of the Summa Halesiana, but that there also seems to be a broad change in Aquinas's approach between his earlier writings and his later thought. In his earlier writings, there is a much more developed approach to synderesis in particular; in his later writings, however, he seems to abandon this approach. ^ Second, I examine Aquinas's fuller analysis of synderesis and conscientia from De Veritate. In this work, Aquinas gives examples of different precepts of synderesis; I then argue that these can be systematized into three different categories of precepts: the foundational precept (that good is to be done and promoted and evil is to be shunned), the criterial precepts (that God is to be obeyed, that one is to live in accord with ratio) that can serve as a basis for judging moral principles, and the material precepts (which are the primary precepts of the natural law). This provides a basis a complex syllogistic structure for the judgment of conscientia by which this judgment can encompass both the application of principles to a particular act and the judgment of whether the moral principles themselves are proper principles for moral judgment. ^ Third, I explore an issue involving whether there is a facet of character that is associated with the desire for the good that is associated with the judgment of conscientia; I argue that it is reasonable to hold that there should be such a facet of character (although this goes beyond the score of Aquinas's work). In adopting a Thomistic approach, I argue that this facet of character should not be seen as either moral virtue or continence; rather, I say that it is different from either of these and I call this facet of character conscientiousness. Finally, I give a tentative examination of the question of how conscientiousness may be developed.^

Subject Area


Recommended Citation

Converse, Aaron William, "An examination of Aquinas's approach to conscience" (2012). ETD Collection for Fordham University. AAI3542746.