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

300 Reciprocal Interiority of the Divine Persons
St Thomas can call on the exegesis of St John Chrysostom which, in this
context, equally accentuates the consubstantiality of Father and Son.5
In its extension of this Wrst line of enquiry which draws on the substantial
unity of the divine persons to account for their communal presence, the
theological tradition developed the more capacious notion of perichoresis
which could also integrate other aspects of the Trinitarian mystery. The
word perichoresis, which can be translated as interpenetration, makes its
Wrst appearance in Christology, becoming clearly observable in the seventhcentury
writings of Maximus the Confessor (following St Gregory Nazianzus,
who had earlier employed the verb perichorein in a Christological sense),
where it is used to mean that, in Christ, the human nature is united and
bonded to the divine nature within a reciprocal communication: there is a
‘perichoresis’ of the two natures in Christ.6 Such perichoresis represents
a reciprocation of activities, the interaction of the divine and human natures
in Christ: the two natures are united, without confusion, in a reciprocal
exchange. Within Christology, it is a consequence of the Council of Chalcedon’s
aYrmation of the hypostatic union: the two natures of Christ are
neither separated nor detached from one another, but united in a reciprocity.
In its second innings, this Christological terminology will be extended to
Trinitarian theory by St John Damascene.7 The Trinitarian notion of perichoresis
makes its appearance within the history of theology after the doctrine
of the Trinity has come to full maturity. When it functions within Trinitarian
theology, perichoresis means the communal immanence, or the reciprocated
interiority of the three persons. Through a kind of reciprocal compenetration,
each person is contained in the other. As John Damascene puts it,
We do not say that there are three gods, the Father, the Son and the Holy Spirit, but
one God . . . They are united but not confused, and they are in one another, and this
perichorěsis (perichôrêsis), each in the others, is without fusion or mixture.8
Perichoresis is an expression of the unconfused unity of the three persons:
it excludes Arianism or tritheism, since each person is contained in the others,
and it excludes Sabellianism, since the three persons remain distinct within
5 See Catena in Ioan. 14.9 (ed. Guarienti, p. 518). This explanation of the reciprocal
immanence of the persons through their identical divine substance will be repeated at the
Council of Florence in 1442 (Bull of Union with the Copts, cf. Denzinger, nos. 1330–1331).
6 See Maximus the Confessor, Opuscula theologica XVI and Ambigua 112 b.
7 For a sketch of the history of this, see P. Stemmer, ‘Perichorese. Zur Geschichte eines
BegriVs’, Archiv für BegriVsgeschichte 27 (1983) [1985], 9–55.
8 John Damascene, The Orthodox Faith I. 8. Cf. The Orthodox Faith I. 14: ‘The hypostases
remain and are each in the others, for they are inseparably and indivisibly one in the others by
their perichoresis (perichôrêsis), one in the others without confusion, nor in fusion or mixture
but by the fact of one being conveyed into the others.’