Ms. Auct. D. Inf. 2.11 F. 59V./Bodleian Library, Oxford

Floating on a rainbow, God watches as the dove returns to the Ark, alerting Noah that the Flood has subsided, in this 15th-century French illumination by the Fastolf Master. God later promises Noah, “When the bow is in the clouds, I will see it and I will remember the everlasting Covenant” (Genesis 9:16). Columnist Leith suggests the rainbow, a colorful manifestation of invisible white light, makes an equally apt metaphor for God, an essentially unknowable deity who appears in the Bible in a wide spectrum of guises.