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

48 The Treatise on the Triune God
natural reason (qq. 2–26), and where conclusive philosophical arguments are
integrated into theology, although not uncritically.46 St Thomas explains that
creatures lead us to the recognition that God exists, and they are also
conducive to ‘know[ing] of God what must necessarily belong to him, as
the Wrst cause of all things, exceeding all things caused by him’.47 Created
things cannot make us know the divine essence as being the essence of Father,
Son, and Holy Spirit, but it induces us to grasp the features which one must
acknowledge as belonging to the divine essence in its capacity as the principle
of creatures; and these essential features are common to the three persons
which are known by their revelation in the history of salvation. The second
instance applies to the distinction of the persons within the Trinity: as we have
recalled earlier, Thomas draws on analogies which, without having demonstrative
force outside of faith, enable one to present the Trinity to believers’
thinking.
(c) The Game Plan of the Treatise on the Trinity
Using the elements which we have just brought to mind (the common and the
proper), and in line with the project of thinking about faith which we sketched
in the previous chapter, Thomas’ thesis aims at giving an account of the
divine persons who are the one God (the common essence), each of whom is
characterized by a personal property (the distinction of persons). The notion
of person as ‘subsistent relation’—which we will look at in detail later on48—
is thus the synthesizing principle of Thomas’ treatise about God. Since the
divine person is to be conceived as a subsistent relation, the study of person
must be preceded by a study of relation: and since our minds perceive
procession as the foundation of relation, the theory of relation requires a
preliminary study of procession. As we try to think about the mystery of the
Trinity, the order in which we conceptualize things will thus be as follows: (1)
the processions; (2) the relations; (3) the persons. Here again one Wnds the
fundamental elements of this meditation, as St Thomas developed them in his
46 Theology does not restrict itself simply to repeating the thinking of philosophers, for
human reason easily commits ‘numerous errors’ about God (ST I, q. 1, a. 1). At the conclusion
of his study of the essential attributes of God, in the Compendium Theologiae, St Thomas
observes: ‘That which we have taught about God has been treated with Wnesse by many pagan
philosophers, even though some have commited errors on this topic’ (CT I, ch. 36). St Thomas
was not satisWed with borrowing and using other people’s philosophy: he created a philosophy.
47 ST I, q. 12, a. 12. This does not refer to everything which could be said about the divine
essence: the treatise on the Trinity will show this by making further reWnements about the
relation of the essence with the divine persons.
48 See below, Chapters 6 and 7.