Alex @ Alexander Pruss’s Blog urges that even non-social trinitarians can make a priori arguments for their trinitarian theology based on the concept of perfection.
I don’t think these sorts of arguments work, as I explain in a comment there, but check it out – Alex is always worth a read, and maybe I’m all wet.
Related posts:
Yet More Theories of the Trinity
Guest Post: Stephen Kershnar on The Mystery of the Trinity
Reflections on the Impossibility of a truly lonely Christian God (Dale)
Christology and Heresy 3 - The basic philosophical issue (JT)
SCORING THE BURKE – BOWMAN DEBATE – Bowman 3
the Bible teaches that David is God
Derivation vs. Generic Theories -- part 3: The Derivation View (JT)
Are atheists denying the obvious? Koukl vs. Rauser and Feser
Pawl's Promise
Richard of St. Victor’s De Trinitate, Ch. 20 (Dale)