Frieze for the Portico of Villa Medici at Poggio a Caiano

The enigmatic imagery of putti emerging toward the left and right from the figure with outstretched arms is thought to represent the birth of time and eternity or souls choosing between a just and unjust life. One textual source may be the Roman poet Claudian's writings about the origins of the universe. The ouroboros, a symbol of eternity as a serpent or dragon eating its own tail, encircles the mountainous form punctuated by a cave in which a man grasps serpents, a conventional symbol of evil. At right, a young male figure holds a compass and armillary sphere, representing just life and the logic and order promoted under Medici rule.