Responding to Basil’s request for a theologically sound understanding of
the term homoousios . . . Apollinarius initially traces this problem back
to two definitions of ousia, according to which the term signifies:
(1) what is said to be ‘one in number’ (μια αριθμω);
(2) what is contained in one ‘description’ (εν μια
περιγραφη).
Of these two, the former appears to be the ‘first substance’ of Aristotle’s
Categories, (Aristotle, Cat. 5 [2a11-13]) the concrete,
countable, individual object. The latter might well be what Aristotle in the
same writing called ‘second substance’, the species and genera. (Aristotle, Cat.
5 [2a14-17]) Second substances are said in Categories to
contain individuals of which the same ‘formula of being’ (λογος της
ουσιας) can be predicated
and Apollinarius term ‘circumscription’ (περιγραφη) could be a substitute for that Aristotelian phrase.
(cf. Aristotle, Cat. 1 [1a1-2])
Apollinarius thus offers a remarkably technical exposition of the
subject, starting from the terminology adopted in the wake of Aristotle’s Categories
by all Neoplatonic logicians since Porphyry. His major argument, however, is
that apart from those two, there is a further understanding of ousia,
and it is this third one which alone in his view is pertinent when it comes to
the Trinity. According to this use, ousia is said of two or more people
united as a ‘family’ (κατα γενος); the term ousia—and
by implication homoousios—can therefore be applied to those who are
connected as parents and children or, more broadly, as ancestors and their descendants.
What this means, Apollinarius goes then on to explain in no uncertain terms.
The members of such a family are ‘the same’ (ταυτον) according to substance;
the descendant is the ‘same’ (ταυτον again) as his progenitor; the while family are ‘one’ (εις).
Apollinarius does not here use the neuter (εν) as we find it,
famously, in John 10, 30 (‘I and the Father are one’), but the masculine form
of the numeral. The family or, indeed, all of humanity, are insofar as they are
all the one person from whom they are descended; ‘All human beings are Adam’; ‘the
son of David is David’. This, precisely, is how Apollinarius thinks this model
applies to the relationship between Father and Son in the Trinity as well. ‘God’,
the divine ousia, is first the Father and then also, by derivation, the
Son, but on account of this relationship it is legitimate to call the Son ‘God’
and also to see the two as one. Otherwise, he notes, the Son could not
be God without violating the principle of monotheism.
This relationship, according to Apollinarius, is different from that
envisaged both in the Platonic, transcendent genus and in the Stoic notion of ‘material
substratum’, the two problematic interpretation Basil had flagged up in his
earlier letter. Characteristically, Apollinarius treats these two in parallel
here: ([Basil], Ep 363, 20-6) they both consider symmetric individuals
partaking in a common item whereas the derivative ousia Apollinarius
stipulates is asymmetric. The unity of its members thus lies not in what is
common to everyone, but in humanity’s derivation from the first human being.
Apollinarius’ argument has remarkable parallels in the philosophy of the
Aristotelian commentators, specifically in their concept of so-called derivative
genera. Aristotle himself had defined them as series in which the first member
of positive integers which, according to ancient mathematics were constituted
of monads, but the monas (1) was also the first member or element in this
series. Aristotle denied that these were proper genera: they do not all fall
under the same definition, therefore there was no univocal predication and, consequently,
no science corresponding to them. Also, Aristotle opined that these genera
would contain members of carrying ontological dignity, which in his view was by
definition excluded in a proper genus. (cf. Aristotle, Met. B [999a6-10]
and EN I 4 [1096a17-19] for the attitude to the same problem
in the Platonic academy)
For late ancient Neoplatonists these quasi-genera, which they named ab
uno (αφ’ ενος) or ad unum (προς εν) genera, had considerable metaphysical attraction
since for them the world as a whole consisted of such derivative series. Within
their logical works, on the other hand, which were those most likely to have
been familiar to a broader readership, derivative genera were still discussed primarily
because of their logical peculiarities although it seems clear that questions
such as whether or not predication ab uno or ad unum is equivocal
or whether it constitutes a third between univocity and univocity (For a
lengthy discussion of the problem cf. Simplicius, In Cat. [31, 22-33; 21
Kalbfleisch]. Philoponus, In Cat. [16, 21-17, 19 Busse] counts
derivative genera as homonyms) would hardly have attracted the interest they
received, had it not been for the fact that their authors had reason to believe
that more or less all real genera were derivative in this sense.
Apollinarius’ letter to Basil clearly indicates that he was aware of
this specific issue. He expressly noted the absence of a common genus term (γενος) predicated (υπερκειται) of Adam and the rest
of humankind: Adam’s property, he wrote, is ‘made by God’ (θεοπλαστος) while we are ‘begotten
by man’ (ανθρωπογεννητοι). Apollinarius does not tell us how it is resolved at the logical
level, but he seems to have been aware of this dimension all the same.
. . .
This emphasis in Apollinarius on cohesion and unity is also noteworthy
in the context of the trinitarian debates. He shows remarkably little concern
for the differentiation between the individual persons whether human or divine.
Consequently, it is far from obvious why the human beings are all ‘Adam’,
whereas the Son is God but not the Father. A theory of hypostases is at best
intimated here but not conceptually worked out. (Johannes Zachhuber, The
Rise of Christian Theology and the End of Ancient Metaphysics: Patristic
Philosophy from the Cappadocian Fathers to John of Damascus [Oxford: Oxford
University Press, 2020], 27-28, 29)