Angel statue praying on its knees

An angel kneeling in full prayer carries the weight of a doctrine particular to medieval theology — that even the highest spiritual beings worship something higher still. Saint Thomas Aquinas, in the Summa Theologiae, devoted long passages to the worship the angels offer God, calling it the perpetual act that constitutes their being. To carve an angel on its knees is to render visible that invisible posture: the great courtier of heaven, forever in the act of bowing.