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:

a quote every theology student working on the Trinity or Incarnation should memorize

The Incarnation of God's Logos (John 1:1-18)

podcast 47 - Dr. Alan Padgett, “Informal Reason and the Idea of a Christian Philosophy”

A Lesson in Christological Rhetoric

On a Rebuttal to my “How Trinity theories conflict with the New Testament” - Part 3

Linkage: Feudin' Christian Philosophers & Theologians

What is the Trinity? A Dialogue with Steve Hays - Part 3

"Only God can forgive sins." False.

Patton's problem with Apologists

