¹ See for instance Edward Feser, ‘The Neo-Classical Challenge to Classical Theism’, Philosophy Compass, 17 (2022), e12863, see also my paper, ‘From God’s Existence to God’s Nature’ in Collected Articles on the Existence of God (Neunkirchen-Seelscheid: Editiones Scholasticae, 2023), pp. 263–73.

² This is clear in his procedure in the Summa Theologiae (Turin: Marietti, 1926), Ia, qq. 2–11 where Thomas first establishes God as the absolute primary cause of all things (qu. 2) and thence establishes the divine attributes on the basis of God’s being the absolute primary cause (qq. 3–11).

³ I defend this reading of Aquinas’s proofs of God in the paper, ‘Aquinas’s Metaphysical Way to God’ in Summa metaphysicae ad mentem Sancti Thomae: Essays in Honor of John F. Wippel, ed. by Therese Scarpelli Cory and Gregory Doolan (Washington: The Catholic University of America Press, 2024).

⁴ See my articles, ‘Essentially Ordered Series Reconsidered’ and ‘Essentially Ordered Series Reconsidered Once Again’, in Collected Articles on the Existence of God. See also Edward Feser, Scholastic Metaphysics: A Contemporary Introduction (Heusenstamm: Editiones Scholasticae, 2014), pp. 148–54, and Five Proofs for the Existence of God (San Francisco: Ignatius Press, 2017), pp. 20–26; Caleb Cohoe, ‘There Must Be a First’, British Journal for the History of Philosophy, 21 (2013), 838–56. One objection to the metaphysics of per se ordered series that has emerged in recent literature is that of existential inertia. There have been several responses to this objection, most of which note that the metaphysics that would motivate the existential inertia objection is quite at odds with Thomistic metaphysics. Hence, a defender of existential inertia would need to justify that metaphysics before pressing the existential inertia objection. See Feser, ‘Existential Inertia and the Five Ways’, American Catholic Philosophical Quarterly, 85 (2011), 237–67; Kerr, ‘Existential Inertia and the Thomistic Way to God’ in Collected Articles on the Existence of God; Jack Bockzar, ‘Existential Inertia and Thomistic Esse’, New Blackfriars (2024), 1–12.

⁵ For Aquinas’s discussion of these causal series, see Aquinas, Summa Theologiae, Ia, qu. 46, art. 2, ad. 7, De Veritate (Turin: Marietti, 1927), qu. 2, art. 10.

⁶ See Aquinas, Summa Theologiae, Ia, qu. 104, art. 2: ‘Cum enim sunt multae causae ordinatae, necesse est quod effectus dependeat primo quidem et principaliter a causa prima; secundario vero ab omnibus causis mediis’; In Librum De Causis Expositio (Turin: Marietti, 1955), Lect. 1, n. 23: ‘…[O]peratio, qua secunda causa causat effectum, causatur a causa prima; nam causa prima adiuvat causam secundam faciens eam operari …’, and n. 28: ‘Causa secunda non agit in causatum suum nisi virtute causae primae. Ergo et causatum non procedit a causa secunda nisi per virtutem causae primae’. For the same see, Summa Theologiae, Ia, qu. 21, art. 4, qu. 65, art. 3, and De Potentia Dei (Turin: Marietti, 1927), qu. 3, art. 4; see also James Alberston, ‘Instrumental causality in St Thomas’, The New Scholasticism, 28 (1954), 409–43; Armand Maurer, ‘Darwin, Thomists, and Secondary Causality’, The Review of Metaphysics, 57 (2004), 491–514, Gaven Kerr, Aquinas and the Metaphysics of Creation (New York: Oxford University Press, 2019), Chapter 4, James Dominic Rooney, ‘The Metaphysics of Creation: Secondary Causality, Modern Science’, in The New Cambridge Companion to Aquinas, ed. by, Eleonore Stump and Thomas Joseph White (Cambridge: Cambridge University Press, 2022), pp. 107–26.

⁷ Aquinas, In Metaphysicorum Aristotelis Expositio (Turin: Marietti, 1950), Lib. V, lect. 2, n. 775: ‘…Efficiens et finis sibi correspondent invicem, quia efficiens est principum motus, finis autem terminus’.

⁸ Aquinas, In V Met., lect. 2, n. 775: ‘Efficiens est causa finis quantum ad esse quidem, quia movendo perducit efficiens ad hoc, quod sit finis. Finis autem est causa efficientis non quantum ad esse, sed quantum ad rationem causalitatis. Nam efficiens est causa inquantum agit: non agit nisi causa finis. Unde ex fine habet suam causalitatem efficiens’; De Principiis Naturae (Rome: Leonine, 1976), Cap. 4, p. 43:16–19: ‘Efficiens enim dicitur causa respectu finis, cum finis non sit in actu nisi per operationem agentis: sed finis dicitur causa efficientis, cum non operetur nisi per intentionem finis’.

⁹ Note Thomas’s insistence that the final cause is the cause of causes, so without it there would be no causality, De Principiis Naturae, Cap. 4, p. 44:29–36: ‘Unde finis est causa causalitatis efficientis, quia facit efficiens esse efficiens: similiter facit materiam esse materiam, et formam esse formam, cum materia non suscipiat formam nisi per finem, et forma non perficiat materiam nisi per finem. Unde dicitur quod finis est causa causarum, quia est causa causalitatis in omnibus causis’.

¹⁰ In I Sent., dist. 38, qu.1, art. 1, ad. 4: ‘…Voluntas habet completam rationem causae, inquantum objectum ejus est finis secundum rationem boni, qui est causa causarum…’; Summa Theologiae, Ia, qu. 5, art. 2, ad. 1: ‘Bonum autem, cum habeat rationem appetibilis, importat habitudinem causae finalis, cuius causalitas prima est, quia agens non agit nisi propter finem, et ab agente materia movetur ad formam, unde dicitur quod finis est causa causarum’.

¹¹ Aquinas of course has other proofs where he considers other kinds of causal actuality; I have argued that in all of these proofs Aquinas makes a move from metaphysical act to a primary cause that is pure actuality. See my article, ‘Aquinas’s Metaphysical Way to God’. For discussion and defence of many of these proofs, see my Collected Articles on the Existence of God, and for a discussion and defence of the way from De Ente et Essentia, see my Aquinas’s Way to God: The Proof in De Ente et Essentia (New York: Oxford University Press, 2015).

¹² A fuller treatment of this issue would incorporate the important principle in Thomas’s metaphysical thought that act is limited by the potency that receives it. Accordingly, the actuality of esse is limited by the distinct potency (the essence) that receives it. So given the different individuals that exist, their esse is delimited to them, and so their causal actuality is a real individual albeit secondary causal actuality. See for instance Aquinas, Summa Contra Gentiles (Turin: Marietti, 1961), Lib. 2, Cap. 52: ‘Esse autem, in quantum est esse, non potest esse diversum: potest autem diversificari per aliquid quod est praeter esse; sicut esse lapidis est aliud ab esse hominis’; De Potentia Dei, qu. 1, art. 2: ‘Esse enim hominis terminatum est ad hominis speciem, quia est receptum in natura speciei humanae; et simile est de esse equi, vel cuiuslibet creaturae’. For discussion see William Norris Clarke, ‘The Limitation of Act by Potency in St. Thomas: Aristotelianism or Neoplatonism?’ in Explorations in Metaphysics: Being-God-Person (Notre Dame: University of Notre Dame Press, 1994), pp. 65–88, John Wippel, ‘Thomas Aquinas and the Axiom that Unreceived Act is Unlimited’, in Metaphysical Themes in Thomas Aquinas II (Washington: The Catholic University of America Press, 2007), pp. 123–51.

¹³ For an illustration of this form of reasoning, see Aquinas, Summa Theologiae, Ia, qq. 5–6. This reasoning occurs within the wider context of the convertibility of being and goodness, the doctrine of the transcendentals. For details, see Jan Aersten, Medieval Philosophy and the Transcendentals: The Case of Thomas Aquinas (Leiden-New York-Cologne: Brill, 1996) note in particular Chapter 7 which deals with good as a transcendental. See also my article ‘Goodness and Being, Transcendentals, Participation’, in The New Cambridge Companion to Aquinas, pp. 85–107.

¹⁴ I have spelled this out in greater detail in Aquinas and the Metaphysics of Creation, Chapter 7.

¹⁵ This is a central feature of Aquinas’s metaphysics of creation viz that God is the cause of the entire substance whole and complete, so that whatever actuality a substance has is derived from God. See for instance, Aquinas, In II Sent., dist. 1, qu. 1, art. 2: ‘Hoc autem creare dicimus, scilicet producere rem in esse secundum totam suam substantiam’. The same definition can be found in: Summa Contra Gentiles, Lib II, Cap. 17, De Potentia Dei, qu. 3, art. 1, Summa Theologiae, Ia, qu. 45, art. 1, Tractatus De Substantis Separatis, Cap. 10, n. 56. For discussion and connection of this issue with creation ex nihilo, see Aquinas and the Metaphysics of Creation, Chapter 3.

¹⁶ Aquinas, Summa Theologiae, Ia, qu. 19, art. 1, ad. 3: ‘…[V]oluntas cuius obiectum principale est bonum quod est extra voluntatem, oportet quod sit mota ab aliquo. Sed obiectum divinae voluntatis est bonitas sua, quae est eius essentia. Unde, cum voluntas Dei sit eius essentia, non movetur ab alio a se, sed a se tantum, eo modo loquendi quo intelligere et velle dicitur motus’; ibid., art. 3: ‘Alia autem a se Deus vult, inquantum ordinantur ad suam bonitatem ut in finem. Ea autem quae sunt ad finem, non ex necessitate volumus volentes finem, nisi sint talia, sine quibus finis esse non potest, sicut volumus cibum, volentes conservationem vitae; et navem, volentes transfretare. Non sic autem ex necessitate volumus ea sine quibus finis esse potest, sicut equum ad ambulandum, quia sine hoc possumus ire; et eadem ratio est in aliis. Unde, cum bonitas Dei sit perfecta, et esse possit sine aliis, cum nihil ei perfectionis ex aliis accrescat; sequitur quod alia a se eum velle, non sit necessarium absolute. Et tamen necessarium est ex suppositione, supposito enim quod velit, non potest non velle, quia non potest voluntas eius mutari’; De Divinis Nominibus, Cap. 3, Lect. 1, n. 228: ‘…[Q]uidquid Deus facit creaturis, sive esse sive vivere et quodcumque aliud totum ex bonitate divina procedit et totum ad bonitatem pertinent creaturae’, and also Cap. 4, Lect. 1, n. 261: ‘…[Q]uidquid in creaturas procedit, hoc creaturae suae propter suam bonitatem communicat’. For discussion see Aquinas and the Metaphysics of Creation, Chapter 2.

¹⁷ See Summa Theologiae, Ia, qu. 22, art. 1, Summa Contra Gentiles, Lib. III, Cap. 95.

¹⁸ Summa Contrra Gentiles, Lib. II, Cap. 68: ‘Semper enim invenitur infimum supremi generis contingere supremum inferioris generis…Est igitur accipere aliquid supremum in genere corporum, scilicet corpus humanum aequaliter complexionatum, quod attingit ad infimum superioris generis, scilicet ad animam humanam, quae tenet ultimum gradum in genere intellectualium substantiarum, ut ex modo intelligendi percipi potest. Et inde est quod anima intellectualis dicitur esse quasi quidam horizon et confinium corporeorum et incorporeorum, inquantum est substantia incorporea, corporis tamen forma’. In III Sent., Proem: ‘…[H]omo enim est quasi orizon et confinium spiritualis et corporalis naturae, ut quasi medium inter utrasque, bonitates participet et corporales et spirituales…’. For a discussion of the notion of man as a horizon, see Gerard Verbeke, ‘Man as a Frontier according to Aquinas’, in Aquinas and Problems of His Time, ed. by G. Verbeke and D. Verhelst (Leuven: Leuven University Press, 1976), pp. 195–223.

¹⁹ This is affirmed with all due reverence, regard, and consideration of those angels revealed in scripture as the allies of humanity. The point is an ontological one pertaining to the being of things.

²⁰ Thomas even goes so far as to claim that the ultimate end of the universe is the beatitude of the saints, Summa Theologiae, Ia, qu. 73, art. 1: ‘Ultima autem perfectio, quae est finis totius universi, est perfecta beatitudo sanctorum; quae erit in ultima consummatione saeculi’.

²¹ Summa Theologiae, Ia, qu. 1, art. 10.

²² Summa Theologiae, Ia, qu. 1, art. 10: ‘Illa ergo prima significatio, qua voces significant res, pertinet ad primum sensum, qui est sensus historicus vel litteralis. Illa vero significatio qua res significatae per voces, iterum res alias significant, dicitur sensus spiritualis; qui super litteralem fundatur, et eum supponit’. See also Quodlibet VII (Turin: Marietti, 1927), qu. 6, art. 2.

²³ Of course, they could also be well aware of Dr Smith’s intentions.

²⁴ Thomas takes the revelation of Exodus as a revelation that God is existence itself, see Summa Theologiae, Ia, qu. 13 art. 11, and in light of this Thomas go so far as to say that this divine name is even more appropriate than the name ‘God’, not only because it signifies existence, but also therein he sees a note of divine simplicity through the incommunicability and singularity signified by the divine name; see ad. 1: ‘…Hoc nomen qui est est magis proprium nomen Dei quam hoc nomen Deus, quantum ad id a quo imponitur, scilicet ab esse, et quantum ad modum significandi et consignificandi, ut dictum est. Sed quantum ad id ad quod imponitur nomen ad significandum, est magis proprium hoc nomen Deus, quod imponitur ad significandum naturam divinam. Et adhuc magis proprium nomen est tetragrammaton, quod est impositum ad significandam ipsam Dei substantiam incommunicabilem, et, ut sic liceat loqui, singularem’.

²⁵ Summa Theologiae, IIIa, qu. 1, art. 3.

²⁶ Ibid, note in particular: ‘…Cum in sacra Scriptura ubique incarnationis ratio ex peccato primi hominis assignetur, convenientius dicitur incarnationis opus ordinatum esse a Deo in remedium peccati, ita quod, peccato non existente, incarnatio non fuisset’.

²⁷ Summa Theologiae, IIIa, qu. 1, art. 2.

²⁸ Ibid, here Thomas lists a number of ways in which the incarnation does indeed achieve these aims.

²⁹ A lingering question would then arise as to why it needs to be revealed that God saves us from sin. Aside from the fact that even on the metaphysics of creation outlined above it is not necessary that God save human beings from sin, should this be known by means of natural reason, it would be known only by a few, after many years of study, and with a number of errors, see Summa Theologiae, Ia, qu. 1, art. 1: ‘Ad ea etiam quae de Deo ratione humana investigari possunt, necessarium fuit hominem instrui revelatione divina. Quia veritas de Deo, per rationem investigata, a paucis, et per longum tempus, et cum admixtione multorum errorum, homini proveniret, a cuius tamen veritatis cognitione dependet tota hominis salus, quae in Deo est. Ut igitur salus hominibus et convenientius et certius proveniat, necessarium fuit quod de divinis per divinam revelationem instruantur’.