What is so radical about the opening of this epic classic is the way in which Milton both follows in the footsteps of other epic authors such as Homer and Virgil but also distinguishes himself from their work. This is seen most clearly in the way that Milton invokes the Holy Spirit as a muse rather than one of the traditional nine muses. Invoking the help of a muse is a sign that Milton places his work well and truly in the same ilk as the work of Homer and Virgil and others. However, at the same time he distinguishes his work from their epics by signifying that he is appealing to the divine spirit, the inspiration for the Bible and the spirit responsible for the creation of all things. Note how he does this in the opening lines of this poem:
And chiefly thou, O Spirit, that dost prefer,
Before all temples th'upright heart and pure,
Instruct me, for thou know'st; thou from the first
Wast present, and with mighty wings outspread
Dovelike sat'st brooding on the vast abyss,
And mad'st it pregnant: what in me is dark
Illumine; what is low, raise and support;
That to the height of this great argument
I may assert Eternal Providence,
And justify the ways of God to men.
Milton therefore radically shows a very different ambition for his work. He aims to deal with matters that go to the very heart of what it is to be human and to also become a cipher of God's will towards mankind. At the same time, Milton also expresses his own utter dependence on God and his need for God's help. Milton therefore begins his poem with a curious mix of both ambition and humility, recognising how his poem fits in to the work of his literary predecessors whilst at the same time stating how he hopes to create a work that surpasses their efforts in its scope.