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

286 Procession of the Holy Spirit
into two persons, precisely because the relations (of paternity and active
spiration) are not in mutual opposition.83 And, for the same reason, if there
were no relational opposition between the Son and the Holy Spirit, they would
be one and the same person, which comes down to Sabellian monarchianism.84
And, as the Wnal step in the argument, the relation of opposition can
only be founded in origin, the sole source of personal distinction in God.85 If
one does not take this step, the aYrmation of the personal distinctness of the
Son and Holy Spirit becomes, not just problematic but self-contradictory. And
intellectus Wdei as a theological endeavour would come to an end.
On the basis of this analysis, the Spirit’s procession a Filio asserts itself as the
means of safeguarding the Spirit’s distinctness from the Son, that is, the Spirit’s
own personality. Thomas authenticates this by reviewing all of the possible
foundations for a real relation, and showing that only an origination of the Holy
Spirit a Filio can found the distinct relation of the Holy Spirit. But could not one
just hold that the Son is engendered by the Father, whereas the Holy Spirit
proceeds from the Father: are not the two modes of generation and procession
enough to distinguish them from one another? According to St Thomas,
this answer to the problem is superWcial: the origin of the Son, as generation,
and that of the Spirit, as procession, are not distinct within the divine nature
which they communicate, but within the purview of the relations they involve,
that is, within relationship to a principle. In other words, the distinction
between the Son’s generation and the Spirit’s procession hinges on their order,
and this order entails that the Spirit proceeds from Father and Son.86
One can see how the exposition works: it is in no way a demonstration of
the Trinity, since the argument presupposes Trinitarian faith. It is a matter of
doing as much as theological reason can to disclose the real distinction of the
persons. Thomas develops a reXection which, because it eliminates every
other suYcient hypothesis, entails the necessity (supposita Trinitate) of relational
opposition and thus of the Spirit’s procession a Patre and a Filio.
(b) Love and the Word
The second argument, which is maintained on through to the Summa, takes
us back to the theological conception of the properties of the Son and the
83 Cf. SCG IV, ch. 24 (no. 3613); De potentia, q. 10, a. 5; ST I, q. 30, a. 2; q. 36, a. 2.
84 In other words: if the Holy Spirit did not proceed from the Son, he could not be personally
distinct from him. There is a long discussion of this in the De potentia, q. 10, a. 5.
85 See above, in Chapter 4, ‘Action, the Source of Relation’.
86 We have said enough about why Thomas thinks this answer is insuYcient: see above, in
Chapter 4, ‘The Order of the Trinitarian Processions’. Cf. SCG IV, ch. 24 (nos. 3615–3616); De
potentia, q. 10, a. 2; q. 10, a. 4; q. 10, a. 5, sol. and ad 1–6; ST I, q. 36, a. 2, sol. and ad 7; q. 40, a. 2.