Milton's use of Classical allusions to pagan mythology follows a well established English poetic tradition begun with Chaucer and, some say, perfected with Spenser in The Faerie Queene. Indeed, the tradition of mixing Christian theology with pagan Classical mythological allusion goes back to the original writing of the oral Beowulf narrative.
Critics differ in opinion on how successfully Milton uses pagan Classical mythological allusion in this poem. Some critics suggest that his attempt fails because his theological message is undermined by the pagan allusions. In this view, there is a distinct contradiction between the literary traditions, between the Biblical tradition and mythical tradition.
Other critics assert that, because of the long tradition in English poetry, the pagan allusions of Classical mythology had been Christianized by Milton's time and symbolized Christian concepts thus no longer advanced pagan concepts.
Milton uses Classical mythological allusions (1) to provide imagery, (2) to enhance Christian concepts and, according to some critics, (3) to represent reformation in the Protestant Christian Church of his time. Examples of these follow.
Provide Imagery: Milton borrows Virgil's "age of old" to describe the hoped for effect of the birth of Christ, that the vanity and corruption of the world will melt away--the dross will melt away--leaving the shinning virtue of holiness in each Christian in its place.
For if such holy Song
Enwrap our fancy long,
Time will run back, and fetch the age of gold, [ 135 ]
And speckl'd vanity
Will sicken soon and die,
And leprous sin will melt from earthly mould,
Enhance Christian Concepts: Milton draws on Latin mythology of the Sun god with a chariot, Axletree, to enhance the Christian concept of Christ as the Light come into the world: Christ's light incorporates the revelation of salvation through the Light.
The Sun himself with-held his wonted speed,
And hid his head for shame, [ 80 ]
As his inferiour flame,
The new-enlightn'd world no more should need;
He saw a greater Sun appear
[Than] his bright Throne, or burning Axletree could bear.
Represent Reformation within the Protestant Church: Milton alludes to the Pythagorean concept of heavenly music produced by "the celestial spheres" as they spin in their orbits, a music beyond human sensory perception. This allusion represents an appeal that humans will now, as a result of Christ's birth, be able to hear the music of heaven and reform their worship to make it holy worship, in other words, to reform worship as practiced by the Christian Church. (Interesting to note that while Chaucer and Spenser emphasized reform of the clergy's practices, Milton seems to be emphasizing the reform of the worship of individual Christians.)
Ring out ye Crystall sphears, [ 125 ]
Once bless our human ears,
(If ye have power to touch our senses so)
And let your silver chime
Move in melodious time;
And let the Base of Heav'ns deep Organ blow,