Labeling Justin a "2nd-century Trinitarian" is, in my view, misleading.
OK. I see it differently. If you're going to discuss the influence of Middle Platonism, or any external philosophical paradigm, you are obliged to take on board the belief engaged by the philosophy, otherwise it seems to me you're making your whole case from a one-sided argument.
While the word "Trinity" and triadic language did appear in the 2nd century (and you rightly point out examples), equating this with being "Trinitarian" in any doctrinally meaningful sense is a problem.
I disagree. Theophilus uses the term to define a relation, there's the nascent doctrine right there.
"Trinitarian" in this discussion inevitably evokes the Nicene understanding of the Trinity (ontological unity, homoousios, co-equality).
OK, but that in itself is problematic, as the council said the barest minimum with regard to the Holy Spirit. It was a Christological definition, not a Trinitarian one, so I'd say 'the Nicene understanding of the Trinity' is misleading, as it did not address the unity of the Three, but just the Two.
Nicaea says nothing about the Holy Spirit other than a belief: "Καὶ εἰς τὸ ἅγιον πνεῦμα." – "And (we believe) in the Holy Spirit".
The Evangelic theologian William Lane Craig argues that the Holy Spirit was believed to be
homoousios by extension – an argument I am sure would not satisfy you – it doesn't satisfy me.
There were eighteen synods and councils between 325 and 381, and none define the Holy Spirit in any terms other than 'proceeds from'.
The Creed of Constantinople (381) says: "And [we believe] in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father, who in unity with the Father and the Son is worshiped and glorified, who has spoken through the prophets."
But quite how He 'proceeds' or what type of 'unity' – bearing in mind the Greek means 'together with' – is not defined.
At the Council of Toledo (400), we have credal statements:
1. We believe in one true God, Father and Son and Holy Spirit, creator of that which is visible and invisible, through whom everything in heaven and on earth was created.
2. This one God also has one divine name – the Trinity.
3. The Father is not the Son, but he has the Son, who is not the Father.
4. The Son is not the Father, but is by nature the Son of God.
5. Also the Spirit is the Paraclete, who himself is neither the Father nor the Son, but proceeds from the Father.
6. Therefore the Father is unbegotten, the Son begotten, the Paraclete not begotten, but is proceeding from the Father
10. This Trinity is distinct in persons, of one substance, virtue, power and undivided majesty, unable to be differentiated.
11. Besides him there is no one else with a divine nature, neither angel nor spirit nor anything else of excellence which one ought to believe to be God.
Anathemas:
2. If anyone should say or believe that God the Father is himself the Son or the Paraclete, let him be anathema.
3. If anyone should say or believe that God the Son is himself the Father or Paraclete, let him be anathema.
4. If anyone should say or believe that the Paraclete, the Spirit, is either the Father or the Son, let him be anathema.
To then apply "Trinitarian" to Justin - even with a "2nd-century" qualifier - suggests in a subtle way a continuity with Nicene doctrine.
I'm suggesting the Church believed in the Father, Son and Holy Spirit from its foundation.
You're implying Justin was on a path directly leading to Nicaea ...
Where have I suggested 'a path directly'? You're reading that onto me. The path is anything but ...
... or was engaged with a less developed version of Nicene Trinitarianism.
No, simply engaged with a version of Trinitarianism.
Nicaea falls short of the Cappadocian definition, which most people think of as Trinitarianism.
"2nd-century Trinitarian" is anachronistic ...
How can it be anachronistic when the very term is in use?
The point is Justin's theology suggests a different kind of divine relationship than the ontological unity that was later defined at Nicaea. McClellan argues it is not a matter of Justin's theology being less developed. Rather, he is operating with a distinct theological paradigm, which was shaped by Middle Platonism, a philosophy in which subordination and hierarchy are inherent in the divine structure.
OK.
I'm not sure who McClellan is accusing of retrofitting Nicene theology onto Justin.
If you and I accept that Justin was heavily influenced by Middle Platonism, then there's the reason why Justin's theology was so short-lived ... it proved insufficient to the task.
He is arguing against interpretations that judge Justin by a 4th-century yardstick by retrojecting Nicene assumptions onto him. To me, he simply challenges this assumption.
As I said, I'm not sure who assumes that?
You cited Polycarp, Ignatius, Theophilus, and Tertullian as evidence for "2nd-century Trinitarianism." However, they are not Nicene Trinitarianism itself, even in a "2nd-century" form. Theophilus, for example, doesn't negate a hierarchical or subordinationist understanding.
Never said they were ... 'Nicene Trinitarianism' is, by definition, 4th century.
My Trinitarianism is 7th century – the Doctrine of Perichoresis (Gk: περιχώρησις
perikhōrēsis, 'rotation'). The term first appears in Maximus Confessor (d. 662), but the verb is used by the Cappadocian Gregory of Nazianzus (d. 389/90). It's latin equivalent is Circumincession.