Philosophy 43140: The Ethics of Thomas Aquinas


Decio 324/631-7327


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Purpose----Texts----Requirements---- Syllabus----Paper Assignments----Notes on the Treatises

Purpose of Course:

A part-lecture/part-seminar course for majors, the purpose of which is to provide the student with an opportunity (a) to see in some depth the relation among the main elements of St. Thomas's general moral theory as laid out in the First Part of the Second Part of the Summa Theologiae, viz., the treatises on beatitude, action, passion, habit, virtue, sin, law, and grace, and (b) to explore in more detail certain specific aspects of these treatises.  We will pay special attention to the ways in which Catholic faith and practice lead St. Thomas to appropriate, correct, and transform classical philosophical notions. We will also note in broad strokes what separates his account of moral theory from contemporary forms of deontologism and consequentialism.


The text for the course is the Prima Secundae itself. I have ordered John Oesterle's Treatise on Virtue for questions 49 - 67, but otherwise will be using my own translations, which can be found at and in Treatise on Law: The Complete Text, which I have also ordered for the course.  I still have some translating to do in the Treatises on Sin and on Grace.  We'll see what happens.  (For any questions in the treatises on sin and grace that you may want to consult but do not have access to in the books ordered or in my online translation, you can go to for the "traditional" translation.)


  • Questions. During the course of the semester each student will be expected to submit a daily question or comment on the readings for that day.  The question or comment should be concise and clearly thought out -- and not ramble on.  This is due by midnight of the day before the assignment.  This, along with class participation, will count for 25% of the course grade.
  • Papers. You will be required to turn in three 7-page papers on assigned topics, each worth 25% of the course grade.  The due dates are September 27 (Memorial of St. Vincent DePaul), November 1 (All Saints Day), and December 8 (Solemnity of the Immaculate Conception).  (For the last paper, you may propose for yourself an alternative topic to the one given below.  If you wish to do this, you must consult me about it before Thanksgiving.)

Tentative Syllabus
  • II. Treatise on Happiness
    • 9/1:  The ultimate end in general.  Reading:  Question 1
    • 9/6:  The object and nature of human beatitude.  Reading: Questions 2-3
    • 9/8:  The prerequisites for and attainment of beatitude. Reading: Questions 4-5
  • III. Treatise on Action
    • 9/13:  Voluntariness and the substance of human acts. Reading:  Questions 6-7
    • 9/15:  The movement of the will. Reading: Questions 8-11
    • 9/20:  Elicited and commanded acts of will.  Reading:  Questions 12-17
    • 9/22:  The goodness and badness of human acts. Reading: Questions 18-21
  • IV. Treatise on the Passions
    • 9/27:  The passions in general. Reading: Questions 22-25
    • 9/29:   Love, hatred, and desire.  Reading:  Questions 26-30
    • 10/4:   Pleasure (or delight) Reading:  Questions 31-34
    • 10/6    Pain (or sadness).  Reading:  Questions 35-39
    • 10/11:  The passions of the irascible appetite. Reading:  Questions 40-48
  • V. Treatise on Virtue
    • 10/13: Habits in general. Reading: Questions 49-54
    • 10/25: Virtue in general. Reading: Questions 55-58
    • 10/27: Intellectual, moral, and infused virtue:  Questions 59-63
    • 11/1:  The properties of the virtues. Reading:  Questions 64-67
    • 11/3:  The Gifts of the Holy Spirit, the Beatitudes, and the Fruits of the Holy Spirit.  Reading:  Questions 68-70
  • VI. Treatise on Vice and Sin
    • 11/8:   The nature of sin. Reading: Questions 71-74
    • 11/10: The causes of sin Reading:  Questions 75-78
    • 11/15: The effects of sin. Reading:  Questions 85-89
  • VII. Treatise on Law
    • 11/17:  The essence, types, and effects of law.  Reading: Questions 90-92
    • 11/22:  Eternal law, natural law, human law, and divine law. Reading: Questions 93-95 and 98-99.
    • 11/29:  The moral precepts and judicial precepts of the Old Law.  Reading: Questions 100 and 104-105.
    • 12/1:    The New Law. Reading: Questions 106-108
  • VIII. Treatise on Grace
    • 12/6: The necessity for grace. Reading: Question 109
    • 12/8: The effects of grace: Reading:  Questions 113-114

Paper Assignments
  1. 7-page paper due Sept. 27:  Take one of the five passions that St. Thomas talks at length about, viz., love, pleasure (or being pleased), pain (or being saddened), fear, or anger.  Lay out in an intelligent, orderly, and concise fashion what St. Thomas has to say about this passion.

  2. 7-page paper due November 1:  Discuss intelligently Question 65, St. Thomas's account of the connectedness of the virtues, i.e., the claim that you cannot have one moral or theological virtue without having all the others or, conversely, that if you lack one of the moral or theological virtues, you lack them all.  The two virtues which turn out to be crucial here are prudence among the moral virtues and charity among the theological virtues.  Your paper should include sections on the connectedness of the moral virtues, the connectedness of the theological virtues, and the relation between the moral virtues and the theological virtues.  (In preparation for this last part, you should also look at Question 63, article 3-4 on the difference between acquired moral virtues and infused moral virtues.)

  3. 7-page paper due December 8:  In various places in the Treatise on Law St. Thomas explicitly discusses the relation between law and virtue.  See, for example, q. 94, a. 3; q. 96, aa. 2-3; q. 100, aa. 2 and 9-10.  In addition, the course has tried to show how virtue and law come together in St. Thomas's moral theory, despite the fact that these are often thought by contemporary philosophers to be competing foundational notions in moral theory.  Using the above cited articles as your starting point, paint an intelligent portrait of the relation between law and virtue in St. Thomas's moral theory.