26 May 2024


There’s a million dollar purse just waiting for you. All you have to do is be the first person to solve one of seven extremely complex maths problems.[1] Some of the conundrums are centuries old and have been attempted by some of the most brilliant minds in history. But in the 24 years since the Millennium Prize Problems were set and the reward offered by the Clay Mathematics Institute, only one has been solved. Unless you had exceptional mastery of higher-order mathematics or were a rare arithmetic savant, you wouldn’t even know where to begin. I, for one, wouldn’t have a clue!

Yet many try. The Clay Institute was convinced that even the hardest questions can be cracked, if enough people turn their minds to them. Money and fame might be some incentive, but it was assumed that the thrill of solving the mystery would be enough to encourage many to try.

The great philosopher Aristotle began The Metaphysics with a short sentence: “All people by nature desire to know.”[2] Socrates and Plato had taught him that the most valuable thing in life is knowledge,[3] and that an unexamined life is not worth living.[4] We humans are inquisitive beings. We want to know stuff: the what, how and why of things. We try to make sense of our world and our experiences, trusting that there is some intelligibility to them. Not only is this drive for knowledge in our DNA, the quest is fulfilling, an excellence we should cultivate.

Aristotle was not the first to say so. Six centuries earlier, King Solomon claimed that the mind is made for knowing, that understanding is a worthy pursuit, and that God is the ultimate source of wisdom.[5] “I prayed, and understanding was given me,” he said, “I called on God, and the spirit of wisdom came to me. I preferred her to sceptres and thrones, accounted wealth as nothing compared to her… I loved her more than health and beauty… For wisdom is an unfailing treasure for mortals, and in the getting of wisdom we obtain friendship with God.” (Wis 7:7-14)[6] Christ, too, called His disciples to be dedicated to the truth, to learn from Him, and so be as wise as serpents.[7]

Modernity also lauds knowledge: Francis Bacon said “knowledge is power”[8] and Helen Keller that “knowledge is love and light and vision”.[9] Yet it has its limits. Socrates recommended humility in our thinking when he said that “the only true wisdom is in knowing you know nothing”.[10] Wittgenstein said that there are things of which we cannot speak and should pass over in silence.[11] Love, suffering and death—though very real—seem to defy even our most observant perceptions, our sharpest concepts, our clearest articulations. We can speak about them to be sure, but often what is said is unsatisfying, doesn’t begin to exhaust what might be said, can’t even capture our own experience.

God is the prime example of the ineffable. He’s not a thing but why there’s any thing at all. Some have dared call Him no thing. The medieval mystic Meister Eckhart said “God is nothing. It is not that He is without being, but so beyond this thing or that, that we might conceive and express. He is Being beyond all being. He is a beingless being.”[12]

Thomas Aquinas said God is “non existens”, “not because God is lacking in being but because God is beyond all beings,”[13] beyond our words, categories and analogies.[14] He has no parts to break down and examine, no beginning or end to plumb.[15] He causes all things to be but is Uncaused, the unmoved Mover, the necessary Existence.[16] “I am who I am”, God once told Moses (Ex 3:14), by which He meant “Yes, I really exist, I am Being itself.” But He was also saying, “Mind your own business. Don’t imagine you can sum Me up and tame Me.” The “I am” God is more elusive than a Millenium Maths Problem.

Which doesn’t mean we can’t say anything meaningful about Him. We can at least clear away what God is not. We can reason to the existence of God and what God’s perfections must be. And we can stretch our language and concepts with analogies about God. Above all, we can rely on what God has revealed about Himself: that God is love; that the Father so loved the world He gave His only Son; that that Son is Word made flesh, the Way, the Truth and the Life, the Bread of angels, the Good Shepherd, the Saviour; that the Spirit of Father and Son is the Spirit of Truth and Comfort and Peace. These things are true, and so is our Bible, our Catechism, our Creed.

So, to say that God is a mystery is not to say we know nothing about Him, but rather to confess we’ll never know everything about Him; He is deeply knowable and yet beyond our grasp. The mystery is both revealed and concealed. But in sending His Son, God made it clear He wanted to communicate with us. The Son is the best One to do that, because He is the Logos, the Word, the communication of the Father. And as God incarnate, He can speak in our language, as one of us.

God doesn’t communicate with us because He’s a blabbermouth. He has a purpose, and it’s for our benefit. From all eternity, the Trinity of persons poured out their love upon each other; in time, they poured it out in creation, and they continue to grace all reality. God wants us to know Him: “Understand this today: that the Lord is God indeed, in heaven above as on earth beneath,” He says. And He wants us to love Him: “Understand this and take it to heart” (Dt 4:32-40).

No mathematician ever figured out the puzzle of the Three-in-One. Yet to the ordinary faithful, God reveals His nature so we might know Whom we love and love Whom we know. And if God’s essence is relational, then those made in His likeness must be relational. If God’s being is love, we who are icons of Him must be people of love. If God’s nature is mission, then we are made for mission too, made to “Go make disciples of all nations: baptising them in the name of the Father, and of the Son, and of the Holy Spirit.” (Mt 28:16-20)

Dear friends, the Church teaches that “Whatever similarity there be between Creator and creature, the dissimilarity is even greater.”[17] Whatever we say about God limps somewhat. Yet we are designed for knowing Him. Our minds grasp with certainty that God is Father, Son and Spirit, and our hearts know with conviction that He loves us beyond measure. Today and always, we ponder and delight in Him, whose Spirit makes us cry out “Abba! Father” and makes us co-heirs with His Son (Rom 8:14-17).

[1] https://www.claymath.org/millennium-problems/

[2] Aristotle, Metaphysics, vol 1.

[3] See for example Plato, Euthydemus, 286a.

[4] Plato, The Apology, 38a5-6.

[5] Prov 1:1-7; 2:1-22; 4:5-7; 15:14; 18:15; 23:23.

[6] cf. Prov 4:6-7; 8:11; 16:16; 20:15

[7] Mt 10:16; Jn 1:14,17; 4:24; 8:32; 14:6,17; 16:13; 17:17; 18:37.

[8] Francis Bacon, Meditations Sacrae (1597); cf. Thomas Hobbes, Leviathan (1668).

[9] Helen Keller, The Story of My Life (1903).

[10] Plato, Apology, 22d.

[11] Ludwig Wittgenstein, Tractatus Logico-Philosophicus (1922).

[12] Meister Eckhart, Sermon 62, in The Complete Works of Meister Eckhart, trans. Maurice O’Connell Walshe (New York: The Crossroad Publishing Company, 2009), 316-317.

[13] St Thomas Aquinas, Summa Theologiae Ia, q.4; q.6; Commentary on the Divine Names, I,iii 77;83-84. See Also Brian Davies OP, ‘Aquinas on What God is Not’ in Revue Internationale de Philosophie, Vol.52, No. 204 (2) (1998), 207; F .C. Coppleston, Aquinas (London: Penguin, 1955), 100.

[14] St Thomas Aquinas, Summa theologiae Ia q.2.

[15] St Thomas Aquinas, Summa theologiae Ia q.3.

[16] St Thomas Aquinas, Summa contra gentiles Ia, q.13; Summa theologiae Ia q.2, art.3

[17] Fourth Lateran Council (1215), Constitution 2 On the Error of Abbot Joachim.


Welcome to St Mary’s Cathedral in Sydney for today’s Mass for the Solemnity of the Most Holy Trinity.

I acknowledge concelebrating with me today His Eminence Michael Cardinal Fitzgerald MAfr OBE, a British cardinal with family connections here in Australia, who for some years headed the Pontifical Council for Interreligious Dialogue, and is an expert in Christian-Muslim relations.

Today we celebrate the central mystery of our Christian faith: that God is Father, Son and Holy Spirit; three persons yet one God. In the names of the Most Holy Trinity we offer our Mass and all our prayers. In the names of the Most Holy Trinity we were baptised. In the names of the Most Holy Trinity we are blessed or bless ourselves. Although it’s a mystery of infinite richness, we ask God today to illuminate our minds so that we might better understand Him and love Him. But first we repent of our sins…