All heart they live, all head, all eye, all ear,
All intellect, all sense; and as they please,
They limb themselves, and colour, shape, or size
Assume, as likes them best, condense or rare.
The lines italicized indicate that Milton is familiar with the doctrine of the schools, and is giving it a turn of his own. Milton's angels, apparently, do not assume a body of air but, remaining in their own ethereal substance, assume what form and colour they choose. Raphael, thus having passed through the air like a bird,
to his proper shape returns
A Seraph winged, &c.
Nash says, speaking of Satan, 'Lucifer (before his fall) an Archangel, was a cleere body, compact of the purest and brightest of the ayre, but after his fall hee was vayled with a grosser substance, and tooke a new forme of darke and thicke ayre, which he still reteyneth.' Pierce Penniless (Grosart), ii. 102. The popular mind had difficulty in appreciating the scholastic doctrine of the purely spiritual nature of angels who do not possess but only assume bodies; who do not occupy any point in space but are virtually present as operating at that point. 'Per applicationem igitur virtutis angelicae ad aliquem locum qualitercumque dicitur Angelus esse in loco corporeo.' The popular mind gave them thin bodies and wondered how many could stand on a needle.
The Scholastic doctrine of Angelic bodies was an inheritance from the Neo-Platonic doctrine of the bodies of demons, the beings intermediary between gods and men. According to Plotinus these could assume a body of air or of fire, but the generally entertained view of the school was, that their bodies were of air. Apuleius was the author of a definition of demons which was transmitted through the Middle Ages: 'Daemones sunt genere animalia, ingenio rationalia, animo passiva, corpore aeria, tempore aeterna.' See also Dante, Purgatorio, xv. The aerial or aetherial body is a tenet of mysticism. It has been defended by such different thinkers as Leibnitz and Charles Bonnet. See Bouillet's note to Plotinus's Enneads, I. 454.