Gregory Nazianzen:
No sooner do I conceive of the One than I am illumined by the Splendour of the Three; no sooner do I distinguish Them than I am carried back to the One.
When I think of any One of the Three I think of Him as the Whole, and my eyes are filled, and the greater part of what I am thinking of escapes me.
I cannot grasp the greatness of That One so as to attribute a greater greatness to the Rest.
When I contemplate the Three together, I see but one torch, and cannot divide or measure out the Undivided Light.
—Gregory of Nazianzen, Orationes, 40:41