The Trinitarian Theology of Saint Thomas Aquinas - El Camino ...

60 The Processions
Word was with God and the Word was God. It was at the beginning with
God’; Jn 14.10: ‘I am in the Father and the Father is in me’), the unity of the
Word and his principle (Jn 10.30: ‘The Father and I are one’). In the Summa
Contra Gentiles, at the end of an explanation comparable to the one given
back in the John Commentary, Thomas concludes that this is the teaching
contained in the Prologue to the Fourth Gospel.45 In his treatise, De rationibus
Wdei, he concludes his exposition by showing that this doctrine allows one to
show that the divine Word is ‘of the same nature as the Father and co-eternal
with the Father, unique and perfect’, that is to say, it enables one to give an
account of the Creed.46
In the Wrst article of the Trinitarian treatise in the Summa Theologiae,
Thomas does not mention ‘generation’: the reader could well be put out by
this, since that is what he is dealing with! St Thomas wants to avoid the
misdirected conception, found in Arianism and Sabellianism, of the generation
of the Son as being like one of the acts which God performs within this
world. So Thomas does not place the notion of ‘generation’ (as the communication
of nature to the engendered) at the beginning of his exposition, but
starts with the intellectual procession of the Word instead, because this
enables one clearly to grasp an immanent action whose issue is consubstantial
with its principle, both being a unity. The analogy of intellectual procession
does not work to the exclusion of all others, but Thomas considers it the most
enlightening. He observes that our world does not provide us with any
examples of procession which could perfectly represent the divine generation,
because the Son is born in identity of substance and eternity with the Father.
‘Hence we need to gather an analogical representation from many of these
modes [which one can observe in creatures], so that what is lacking in one
may be partially supplied by another...Yet,within all these likenesses, it is the
procession of the word which represents [divine generation] in the most
adequate way.’47 It is here that one eVectively Wnds the deepest intimacy. So
here the theologian deploys an analogy which, primarily, suits the spiritual
perfection of God; and which, secondly, enables one to grasp clearly what
procession is like in God; and, thirdly, roots it apart from where Arius and
Sabellius had so unproductively planted it.
In the second moment of his exposition, St Thomas shows that the procession
of the Word allows one to know that which in God is the generation of
the Son. In our world, generation comes about in diverse ways. It is an
observable fact for every being which undergoes genesis: it is ‘the passage
45 SCG IV, ch. 11 (no. 3473).
46 De rationibus Wdei, ch. 3. 47 ST I, q. 42, a. 2, ad 1.