¹ I quote from Brian Davies and Brian Leftow (ed.), Thomas Aquinas: Summa Theologiae Questions on God (Cambridge University Press: Cambridge, 2006), 28.  In what follows, I quote from this volume using the abbreviation ‘Davies and Leftow’.

² In what follows, I make reference to Professor Swinburne only since I take him to be an especially famous representative of a way of thinking about God that is currently much in vogue among contemporary Anglo-American philosophers of religion.  In philosophical jargon, I take Swinburne to be a token of a type.

³ Richard Swinburne, The Coherence of Theism (Revised Edition, Clarendon Press: Oxford, 1993), 1.  In this book Swinburne focuses on what God is.  In its sequel, The Existence of God (Revised Edition, Clarendon Press: Oxford, 1991), Swinburne offers arguments in favor of theism.

⁴ The Coherence of Theism, 52.

⁵ Swinburne argues for these conclusions in Chapter 12 of The Coherence of Theism.

⁶ Richard Swinburne, Is There a God? (Oxford University Press: Oxford, 1996), 5.

⁷ Davies and Leftow, 21.

⁸ Aquinas tends to distinguish sharply between knowledge and belief.  He takes belief to involve conviction without seeing, and he takes knowledge to amount to recognizing that a proposition is true and why it is true.  In the Summa Theologiae, this distinction surfaces particularly clearly in Aquinas's discussion of what he calls the theological virtue of faith (Summa Theologiae, 2a2ae,1–7).

⁹ Davies and Leftow, 25–26.

¹⁰ Roughly speaking, Aquinas takes a thing's form to be what we refer to when saying what kind of thing it is or what it is like in various ways.  And (again roughly speaking) he takes matter to be what allows something to change either by passing out of existence or by being modified somehow.  So, for example, being feline is a form had by my cat, and my cat's being able to perish is due to it being material.

¹¹ 1a,3,1 (Davies and Leftow, 30).

¹² 1a,3,2 (Davies and Leftow, 32).

¹³ Cf. Summa Theologiae, 1a,3,5: ‘Since the genus of something states what the thing is, a genus must express a thing's essence.  But God's essence is to exist …  So, the only genus to which God could belong would be the genus of being.  Aristotle, however, has shown that there is no such genus: for genera are differentiated by factors not already contained within those genera, and no differentiating factor could be found that did not already exist (it could not differentiate if it did not exist).  So we are left with no genus to which God could belong’.  I quote from Davies and Leftow, 37.

¹⁴ Davies and Leftow, 38.

¹⁵ G.E.M. Anscombe and P.T. Geach, Three Philosophers (Basil Blackwell: Oxford, 1961), 122.

¹⁶ Davies and Leftow, 35.

¹⁷ Davies and Leftow, 163.

¹⁸ Davies and Leftow, 163.

¹⁹ For a trenchant defense of this position drawing on Gottlob Frege (1848–1925), see C.J.F. Williams, What is Existence? (Clarendon Press: Oxford, 1981).  Williams applies this position, while explicitly targeting Aquinas for criticism, in Chapter 27 of Philip L. Quinn and Charles Taliaferro (ed.), A Companion to Philosophy of Religion (Blackwell: Oxford, 1997).

²⁰ Aquinas's most detailed defense of this conclusion comes in his De Aeternitate Mundi (‘On the Eternity of the World’).  In the Summa Theologiae he touches on the conclusion in 1a,46,2.

²¹ I quote from Volume 8 of the Blackfriars edition of the Summa Theologiae (Eyre and Spottiswoode: London, and McGraw Hill: New York, 1967), 27.

²² I quote from Volume 8 of the Blackfriars edition of the Summa Theologiae, 69 and 71.

²³ This is what Aquinas argues in his commentary on Aristotle's Physics.  I quote from Timothy McDermott (ed.), Thomas Aquinas: Selected Philosophical Writings (Oxford University Press: Oxford and New York, 1993), 83 and 84.

²⁴ For Flew, see Antony Flew, ‘Theology and Falsification’ in Antony Flew and Alasdair MacIntyre (ed.), New Essays in Philosophical Theology (SCM Press: London, 1955), 97.

²⁵ Tractatus Logico-Philosophicus, 6.44.

²⁶ This point is developed by Herbert McCabe in Chapter 2 of Herbert McCabe, God Still Matters (Continuum: London, 2002).

²⁷ The Latin text here reads: ‘Voluntas divina est intelligenda ut extra ordinem entium existens, velut causa quaedam profundens totum ens et omnes eius differentias’.  I quote from Timothy McDermott, Thomas Aquinas: Selected Philosophical Writings, 282–283.

²⁸ In 1a,13,2 Aquinas rejects the view that all positive sounding statements about God are to be construed as denials.  Perhaps wrongly, he attributes this view to Maimonides (1135–1204) while understanding it to amount to the claim that sentences like ‘God is F’ should be understood as always denying something of God, that, for example, ‘God is good’ means ‘God is not bad’, or that ‘God is living’ means ‘God is not inanimate’.  Aquinas rejects this view, though without giving up on his claim that we do not understand what God is. For what seems to be a different reading of Aquinas here, see Eleonore Stump, ‘God's Simplicity’, which is Chapter 10 in Brian Davies and Eleonore Stump (ed.), The Oxford Handbook of Aquinas (Oxford University Press: Oxford and New York, 2012).

²⁹ Aquinas thinks that omne agens agit sibi simile (which we might translate as ‘every agent cause acts so as to produce what reflects it’).  He does not mean that, for example, when I poach an egg I have to look like a poached egg.  He means that poached eggs produced by me can, once we have made the right causal connection, be thought of as reflecting what I am as a potential poacher of eggs.   He means that, typically, a cause (an agent or efficient cause) is something exerting itself, something that has an influence and imposes its character in some way, albeit not always in a way that results in a look-alike of itself (as, say babies, literally look like their parents by being human).  For a short but reliable account of Aquinas on causality see Appendix 2 to Volume 3 of the Blackfriars edition of the Summa Theologiae (Eyre and Spottiswoode: London, and McGraw Hill: New York, 1964).

³⁰ Davies and Leftow, 139–140.

³¹ Davies and Leftow, 165–166.

³² Davies and Leftow, 144.

³³ Volume 3 of the Blackfriars edition of the Summa Theologiae (Eyre and Spottiswoode: London and New York, and McGraw-Hill: New York, 1964), 104.

³⁴ Herbert McCabe, Appendix 3 to Volume 3 of the Blackfriars edition of the Summa Thelogiae).

³⁵ For what it is worth, I would note that the formula ‘God is a person’ does not appear in the Bible, though, of course, the Bible is full of personal and other imagery when it comes to God.  As far as have been able to discover, its first occurrence in English appears in the report of a heresy trial held in Gloucester, UK, in 1664.  The accused individual was someone called John Biddle. The charge against him was that he claimed that God is a person.  This claim was taken to be heretical as contradicting the orthodox doctrine of the Trinity according to which God is three persons in one substance.  For more on this, see Philip Dixon, Nice and Hot Disputes: The Doctrine of the Trinity in the Seventeenth Century (T&T Clark: Edinburgh, 2003).

³⁶ The Summa Theologiae's teaching on God amounts to much more than I have just reported since, in spite of what I have been saying and because it is the work of a teacher of sacra doctrina (‘holy teaching’ or teaching concerning what Aquinas took to be divine revelation), it is grounded in belief in the doctrine of the Trinity. So, for Aquinas, God is not just the incomprehensible creator but is also and from eternity Father, Son, and Spirit.  See Summa Theologiae, 1a,33-43.  As Aquinas develops his account of the Trinity, the differences between him and those who think of God as a relatively understandable person simply leap off the pages that he writes, though I have no space to dwell on them here.

³⁷ Victor White, God the Unknown (Harvill Press: London, 1956), pp.18–19.  For a magisterial account of Aquinas and what we can know God to be, one which ranges over many of Aquinas's writings, see Chapter XIII of John Wippel, The Metaphysical Thought of Thomas Aquinas (The Catholic University of America Press: Washington, D.C., 2000).