Built on
The Summa's treatment of happiness and the virtues is built on Aristotle's Nicomachean Ethics, which it cites constantly, calling Aristotle simply 'the Philosopher'.
Summa Theologiae I-II, qq. 1–5 and 55–67
Built on
Physics · Aristotle · c. 350–330 BC The first of the Summa Theologiae's Five Ways, the argument from motion, follows Aristotle's Physics.
Summa Theologiae I, q.2, a.3
Built on
In Christian Writings
The Summa's questions on the life of Christ cite Chrysostom's homilies on Matthew again and again.
Summa Theologiae III, qq. 27–59 (e.g. q. 44)
Built on
In Christian Writings
The Summa's treatise on the Trinity (Part I, qq. 27–43) relies throughout on Augustine's On the Trinity, including his account of the Holy Spirit as Love.
Summa Theologiae I, qq. 27–43
Built on
The Summa's question on peace adopts Augustine's definition from The City of God (XIX.13): peace is 'the tranquillity of order'.
Summa Theologiae II-II, q. 29, a. 1
Built on
The Summa cites Dionysius hundreds of times, especially the Divine Names on how we can speak of God and the Celestial Hierarchy on the angels.
Summa Theologiae I, qq. 13, 50–64, 108
Built on
The Summa adopts the definition of eternity from Boethius's Consolation of Philosophy: the whole, simultaneous, and perfect possession of endless life.
Summa Theologiae I, q. 10, a. 1; Consolation V.6
Built on
In Christian Writings
The Summa Theologiae draws on Gregory's Pastoral Rule for its treatment of the bishop's office, citing it on when that office may rightly be sought.
Summa Theologiae II-II q.185
Built on
In Christian Writings
The Summa cites John of Damascus ('Damascene') often in its questions on Christ, following his Exact Exposition on how Christ's two natures are united.
Summa Theologiae III, qq. 2–26
Responds to
The Summa rejects the Proslogion's argument: Aquinas denies that God's existence is self-evident from the idea of 'something than which nothing greater can be thought', though he doesn't name Anselm.
Summa Theologiae I, q. 2, a. 1, obj. 2 and ad 2
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In Christian Writings
The Summa Theologiae takes its definition of satisfaction from Anselm's Why God Became Man: satisfaction gives God due honour. (The passage is in the Supplement, completed after Aquinas's death from his earlier writing.)
Summa Theologiae, Supplement q.12 aa.2–3
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In Christian Writings
The Summa Theologiae answers whether God should be loved without measure with Bernard's On Loving God: 'the measure is to love Him without measure.'
Summa Theologiae II-II q.27 a.6, sed contra
Built on
In Christian Writings
Aquinas, who had already commented on Lombard's Sentences, wrote the Summa as a better-ordered textbook for beginners than the Sentences, and it still argues with 'the Master' by name.
Summa Theologiae, Prologue; II-II, q. 23, a. 2 (on "the Master" of the Sentences)
Built on
The Summa Theologiae draws on 'Rabbi Moses', Maimonides' Guide, on the names of God and on whether the world had a beginning.
Summa Theologiae I, q.13, a.2; q.46, a.1