Commentary Purg II 19-30

The gradual revelation of the approaching presence (more light, greater size, two elements of white that then resolve to three [two wings and the angel's 'body']) culminates in Virgil's recognition of the angelic nature of the steersman.  For a brief account of the nature of and doctrinal problems inherent in Dante's angelology see Alison Cornish (Corn.2000.1).

      The term galeotto (helmsman, steersman) has been used for Phlegyas, who carried Dante and Virgil across Styx in his skiff ([Inf VIII 17] -- galeoto).  It had previously been used by Francesca ([Inf V 137]), as a proper noun, to cast blame upon the character Gallehault in the Arthurian romance that led, according to her, to her undoing.  The present galeotto is surely to be understood as a better-intentioned guide.  Dante has been cleansed by Virgil to be in the purified condition fitting for his presence before exactly such a being, 'il primo ministro... di paradiso' ([Purg I 98-99]).  Hell had its guardian demons; purgatory has guardian angels.