The Parable of the Holy Trinity (scene 12, south wall)

The Parable of the Holy Trinity is scene 12 on the south wall of the Sant'Agostino cycle painted by Benozzo Gozzoli in 1464. This episode depicts Augustine on the beach at Ostia, where a child appeared and explained that it was as impossible to pour the entire sea into a hole in the sand as it was for Augustine to comprehend the mystery of the Trinity in his theological treatise De Trinitate. The story served as a lesson in the limits of human intellectual ambition before divine mystery, and Gozzoli renders the seaside encounter with his characteristic blend of narrative clarity and local landscape observation.

The coastal setting is unusual within the cycle and gives Gozzoli scope to render water, sand, and sky in a way that contrasts with the more architectural or urban scenes elsewhere on the south wall. The child figure is rendered at a smaller scale than Augustine, though the hierarchical relationship between the human theologian and the divine messenger complicates any simple reading of their relative sizes. The tonality is lighter and more airy than in the cycle's interior scenes.