A stunningly good meditation on Massacio’s Holy Trinity (1425) in the Wall Street Journal, of all places, by art historian Jack Flam:
The perspective in this painting is sufficiently accurate to be convincing, but purposely inexact enough to make space for the supernatural. This is strikingly evident in the representation of God the Father, who stands on the narrow ledge attached to the back wall of the barrel-vaulted space, which would appear to be about nine feet deep. Yet at the same time, He is also present at the front of this same vaulted space, supporting the body of his Son on the cross. This discrepancy in perspective allows God to be in more than one place at a time—a supernatural phenomenon made all the more remarkable by the painting’s apparent realism.
Among other things, this great fresco, painted on the wall of a Dominican church, is a stunning affirmation of the great Dominican theologian St. Thomas Aquinas’s assertion that to be “everywhere primarily and absolutely is proper to God.” What better place could there be to state this with such subtlety than in a representation of the Holy Trinity, whose paradoxical consubstantiality—distinct, yet of one being—is a central mystery of Christian faith.