There is no subject where a mistake is more dangerous, or the search more laborious, or discovery more advantageous than the unity of the Trinity: of the Father, the Son and the Holy Spirit.
Augustine’s remark, which Peter Lombard put on the Wrist page of his study of the Trinity in the Sentences,1 gives us the Favour of Trinitarian refection in the golden age of scholasticism.
As St Thomas’ Master, Albert the Great saw the matter, precisely because it belongs to this Weld, to show the goal of human existence—making mistakes here will divest faith and theology of their purpose: ‘The whole of human knowledge comes to fruition in knowledge of the Trinity.
For every science and every thing to which the mind applies itself is looking for that which gives us happiness. Speaking about other things is only worthwhile when it derives from and guides us to this search.’
2 St Thomas would follow that up by saying that, ‘The whole of our life bears fruit (fructus) and comes to achievement (Wnis) in the knowledge of the Trinity.’
3 This ‘knowledge of the Trinity’ is supplied by Christian faith, and so paves the way for the vision of the Trinity. It is the way to happiness: ‘The Lord taught that the knowledge that makes us happy consists in knowing two things: the divinity of the Trinity and the humanity of Christ.
’4 Faith in the mystery of Christ enshrines and implies faith in the Trinity.
5 Within the pilgrimage of faith made in the hope of happiness, the theologian’s vocation consists in giving an account of the mystery which he has received, after the pattern of 1 Peter 3.15, a verse which St Thomas loved to quote in order to describe the task to which he dedicated his life within the Order of St Dominic: ‘Always be prepared to satisfy everyone that asketh a reason for the hope and faith which are in you.
’61 Augustine, De Trinitate I.III.5; Peter Lombard, I Sent. dist. 2, ch. 1 (vol. I/2, ed. PP. Collegii
S. Bonaventurae ad Claras Aquas, Grottaferrata, 1971, p. 62).
2 Albert, I Sent. d. 2, a. 6–7.
3 Thomas, I Sent. d. 2, exp. text.
4 CT I, ch. 2. See De ration bus Wide, ch. 1; De articles Wdei I. 5 ST II–II, q. 2, a. 8.
6 St Thomas usually cites a version of this verse which refers to faith (hope and faith); see De ration bus Wide, ch. 1; ST II–II, q. 2, a. 10, sed contra; q. 10, a. 7, ad 3; etc. On the history of this theological emblem, see J. De Ghellinck, Le Movement the ́ololiuqui du XIIe sie`cle, Brussels and Paris, 1948, pp. 279–284.
Reelecting on the Trinitarian faith is thus the theologian’s primary task and this is where the heart of St Thomas’ teaching rests.
7 A fresco in the Dominican monastery of St Anne in Nocera Inferior in Campania bears witness to the central role which Trinitarian faith played in Thomas’ life.
St Thomas is pictured in this icon as one who has received the gift which the Trinity makes of itself to the saints.
Images like this are not common within the iconography of the Dominican saint, which usually displays divergent motifs, like his triumph, his meditation on the Blessed Sacrament, his prayer before the Crucis, his composing the Noyce of the Blessed Sacrament, and so on, along with various insignia, like the chair, the dove, and the lily.
In a collection of frescos dating from the fourteenth and fifteenth centuries, in the monastery of St Anne, Thomas is set between St Paul and St Lucy, and pictured with a pen and a book, two recurrent Wagers in his iconography.
8 The book pictured here is not the Summa Theologian, but the ‘Writing on the Sentences’, and we can see its Wrist lines, taken from Ecclesiasticus, I, Wisdom have poured out rivers (Ecclus 24.40, in the Vulgate).
St Thomas’ prologue to the ‘Writing’ explains that Wisdom refers to the person of the Son: Wisdom who reveals the Trinity in its intimate mystery and in its works, Wisdom who creates, Wisdom who saves the world through his incarnation, and leads humankind to the Father’s glory.
9 When the believer looks at the Son–Wisdom, he is engaged in contemplation of the creative and saving Trinity. And the artist at Nocera has depicted the Trinity as dwelling in the heart of the Dominican master.
This icon represents a Trinity as ‘two heads with the dove between them’, an iconographic type which is fairly infrequent and of which one Winds almost no trace after the fifteenth century.
10 Here it suggests the Pauline and Johannine idea of the indwelling of the divine persons: ‘We will make our abode in him’ (Jn 14.23).
