The painting is "for Aquinas" because of its displaying a certain (for me) vivid crudity of which I am currently and joyfully in pursuit. The "Dumb Ox" Aquinas reference comes from G.K. Chesterton's brilliant study, Saint Thomas Aquinas:The "Dumb Ox" (Image Books, 1959). "Saint Thomas was so stolid," writes Chesterton, "that the scholars, in the schools which he attended regularly, thought he was a dunce" (p.21).
Chesterton also observes that "The saint is a medicine because he is an antidote" (p. 23).