Fr. Stephen Brock

Stephen Brock
Visiting Faculty (2017-18 to 2023-24)
Stuart Hall, Room 202-A
Office Hours: Autumn Quarter:
PhD, University of Toronto, 1988
Teaching at UChicago since 2017
Research Interests: Medieval Philosophy

Since 1990 Professor Brock has taught medieval philosophy at the Pontifical University of the Holy Cross in Rome. He was a visiting professor at the Catholic University of America in 1999, and at the University of Chicago starting in 2017. His research has been mainly on the thought of Thomas Aquinas, in the areas of ethics, action theory, and metaphysics, with occasional ventures into theology.

Selected Publications

Action & Conduct: Thomas Aquinas and the Theory of Action, The Catholic University of America Press, 2022

The Light that Binds: A Study in Thomas Aquinas's Metaphysics of Natural Law, Pickwick Publications (2020)

The Specification of Action in Aquinas: Nonmotivating Conditions in the Object of Intention,” The Thomist (2019)

Dead Ends, Bad Form: The Positivity of Evil in the Summa theologiae,” in Aquinas’s Summa Theologiae: A Critical Guide, ed. Jeffrey P. Hause, Cambridge U. Press (2018)

Formal Infinity, Perfection, and Determinacy in the Metaphysics of St. Thomas Aquinas,” Forum: Supplement to Acta Philosophica (2016)

The Philosophy of Saint Thomas Aquinas: A Sketch, Cascade Books (2015)

Intentional Being, Natural Being, and the First-Person Perspective in Thomas Aquinas,” The Thomist (2013)

The Causality of the Unmoved Mover in Thomas Aquinas’s Commentary on Metaphysics XII,” Nova et Vetera (2012)

On Whether Aquinas’s Ipsum Esse Is ‘Platonism’,” The Review of Metaphysics (2006)

Causality and Necessity in Thomas Aquinas,” Quaestio (2002)



Recent Courses

PHIL 20002 Thomas Aquinas’s Metaphysics of Morals: The Goodness and Badness of Human Actions

(FNDL 21002)

Thomas Aquinas’s account of the goodness and badness that are proper to human actions—moral goodness and badness—is fundamental for his entire ethical teaching. It provides the rationale for his way of dividing human actions into kinds; it sets the reference points for his theory of virtues and vices, which he takes to be nothing other than principles of good and bad actions; it explains the moral function that he ascribes to law; and so on. The aim of this course will be to understand and think about that account. Its fullest presentation is found in Aquinas’s masterpiece, the Summa theologiae. However, the Summa’s approach to ethics is heavily metaphysical, and nowhere is this more true than in its treatment of moral goodness and badness. We shall therefore need to consult background passages from other parts of that work and other works of his, on such metaphysical topics as good and bad in general, powers and their objects, the nature of circumstances, and the relation between intellect and will. We shall also want to consider to what extent the account depends on strictly theological notions. (A)   

Completion of the general education requirement in humanities is required.

2024-2025 Spring
Medieval Philosophy

PHIL 20004 Aristotle’s Physics with Aquinas’s Commentary

(FNDL 20004)

In the Physics, Aristotle lays out the general concepts and principles governing his teachings about the natural world.  His approach is both philosophically sophisticated and quite different from that of modern science.  We will work through substantial selections from Books I-III, with the help of Aquinas’s glosses, which make them more digestible without diluting them.  Topics include the subject and procedure of natural science, the relation of that science to metaphysics and mathematics, matter and form as principles of change, the concept of nature, causality, chance, teleology, the nature of motion, action and passion, and the categories of being. (B)

Students not majoring in Philosophy or Fundamentals need the consent of the instructor.

2024-2025 Autumn

PHIL 21723/31723 The Will: Aristotle, Augustine, Aquinas

Aristotle’s approach to ethics is sometimes termed intellectualist, meaning that it has no room for a notion of the will, understood as a principle of human action distinct from intellect or reason. Such a notion, it is said, gained currency only centuries later, at least partly through influences alien to Greek philosophy. St Augustine is often cited as one of the thinkers most responsible for the notion’s becoming prevalent. St Thomas Aquinas, however, presents a highly articulated theory of human action that appears to integrate a robust conception of the will, and one heavily indebted to Augustine, into a largely Aristotelian framework. We will read and discuss substantial passages from these three authors bearing on the question of the will, in the hope that seeing them side by side can help to get at what they really mean and what the philosophical merits of their views are. (A) (IV)

Undergraduates who are not Philosophy majors must obtain the instructor’s consent.

2023-2024 Autumn
Medieval Philosophy

PHIL 20005 Thomas Aquinas’s Philosophy of Love

Thomas Aquinas is sometimes labeled an “intellectualist,” because of the priority that he assigns to intellect or reason in human life. Nevertheless he treats love as a fundamental principle, not only of human life but of absolutely all life and even all reality, and he thought and wrote extensively about it.  In this course we will read and discuss sizeable passages, from several of his works, concerning the nature of love in general, its various kinds, its causes and effects, how it exists in different subjects — human, angelic, divine, and even non-rational — and what it has to do with morality, virtue, and happiness. As regards the history of the topic, the we shall especially want to consider how Aquinas’s thought on love relates to that of Aristotle and to the Platonic tradition. (A)

Completion of the general education requirement in humanities is required.

2022-2023 Spring

PHIL 20098/30098 Medieval Metaphysics: Universals from Boethius to Ockham

Any language contains terms that apply truly, and in the same sense, to indefinitely many things; for instance, species- or genus-terms, such as hippopotamus or animal. How things admit of such “universal” terms has engaged philosophers ever since Plato, who proposed participation in the forms. In the third century, the Neoplatonist Porphyry wrote an introduction to Aristotle’s Categories, in which he raised, but did not even try to answer, three metaphysical questions: whether genera and species are real or only posited in thoughts; whether, if real, they are bodies or incorporeal; and whether, if real, they are separate entities or belong to sensible things. At the beginning of the medieval period, another Neoplatonic thinker, Boethius, took up Porphyry’s questions. He offered a strict definition of universals, explained the difficulty of the questions, and proposed (without fully subscribing to) what he took to be Aristotle’s way of answering them. Boethius’s treatment oriented the approach to universals by philosophers up through the 12th century. The tools at their disposal, however, were mostly those provided by ancient logical works; and perhaps for this reason, the discussion reached a kind of impasse. But then there appeared translations of numerous hitherto unknown writings of Aristotle and Arab thinkers. Aristotle’s hylomorphism and his doctrine of (what came to be called) abstraction, together with the notion of “common nature” proposed by Avicenna (also a Neoplatonist), seemed to show a way out of the impasse. But they also raised new questions of their own—partly because of their sheer difficulty, and partly because of theological pressures, in the late 1200s, against the standard Aristotelian account of individuation by “matter.” The topic of universals thus tracks various other prominent themes in medieval metaphysics. We will look at background passages in Aristotle and Porphyry, and study texts of some of the most important authors, including Boethius, Abelard, Avicenna, Aquinas, Scotus, and Ockham. (B) (III)


Undergraduates who are not philosophy majors must obtain the instructor’s consent.


2022-2023 Autumn
Medieval Philosophy

PHIL 25101/35101 Aristotle’s De Anima with Aquinas’s Commentary

(FNDL 24309)

There is perhaps no better introduction to Thomas Aquinas’s philosophy of human nature than his still influential commentary on Aristotle’s classic treatment of soul and its powers, the De anima. Writing the commentary was in fact part of Thomas’s preparation for the section on man in the Summa theologiae. Naturally he also had other sources, but he drew much of his method and many of his terms and principles from Aristotle’s work. Our default text consists of English translations of the commentary and of the nearly word-for-word Latin rendering of the De anima that Thomas used. We will work through the entire text; our main goal will be simply to understand it. (B) (IV)

If possible, our classroom will be screen-free. Undergraduates should either be Philosophy majors or obtain the consent of the Professor.

2021-2022 Spring
Medieval Philosophy

PHIL 25102 Aquinas on Justice

(FNDL 24304)

Aquinas regards justice as the preeminent moral virtue, and in the Summa theologiae he devotes more Questions to it than to any other virtue (II-II, qq. 57-79). With occasional help from other passages of his, and with an eye to his sources (especially Aristotle) and to later thinkers, we will first work through his general accounts of the object of justice (ius—the just or the right), justice as a virtue, the nature of injustice, and the distinction between distributive and commutative justice. Then, as time permits, we will discuss selected texts on more specific topics such as judicature, restitution, partiality, murder, theft, verbal injuries, fraud, and usury. (A)

Completion of the general education requirement in humanities. 

2021-2022 Autumn

PHIL 23402 Augustine’s Confessions

(FNDL 23404 )

We will study this work in its entirety, chiefly from a philosophical point of view.  The more popular, more autobiographical Books (I-IX) already offer a good deal of philosophical material; themes treated include the will, friendship, good and evil, knowledge, truth, incorporeal reality, and divine providence.  Then come the more impersonal Books (X-XIII), which present extended and sometimes impassioned inquiries into the natures of memory, time, eternity, and creation.  Latin would be helpful, but it is not required. (A)

Students with majors other than Philosophy or Fundamentals need the permission of the instructor.


2020-2021 Spring

PHIL 20004 Thomas Aquinas’s Commentary on Aristotle’s Physics

(FNDL 20004 )

In the Physics, Aristotle lays out the basic concepts and principles governing his thought about physical reality.  His approach is both philosophically sophisticated and quite different from that of modern science.  We will work through substantial selections, especially from Books I-IV and Book VIII, with the help of Aquinas’s expositions, which make them more digestible without diluting them.  Topics to be treated include the principles of change, matter and form, the concept of nature, causality, teleology, motion, the infinite, place, time, the duration of the physical world, and the primary mover. (B)

Students with majors other than Philosophy and Fundamentals need the permission of the instructor.

2020-2021 Autumn