The reasons for Milton's changed attitude toward his epic poem seem apparent. The changes in Milton's life are ample reasons for artistic changes. In the years between his Latin poems in which the epic theme of King Arthur is raised, Milton had seen his political fortunes rise and fall, had lived in hiding, had been imprisoned and freed with loss of prestige and reputation, had seen his hopes for a Christian nation fall apart, had gone blind, and had suffered through the deaths of two wives and two children. The young man filled with idealistic enthusiasm and nationalistic pride had been replaced by a man who now looked for a Christian hero who might embody "the better fortitude / Of Patience and Heroic Martyrdom," as he says in the prologue to Book IX of Paradise Lost. In the same prologue, he adds that he does not wish "to dissect / With long and tedious havoc fabl'd Knights / In Battles feign'd." None of such mainstays of earlier epics, he adds, give "Heroic name / To Person or to Poem."
Milton's whole concept of what an epic subject should be had changed. War, conquest, heroism in battle seemed like shams, and in Book VI of Paradise Lost, he wrote battle scenes that mock the epic convention. By the time he wrote his epic, Milton had found true heroism in obedience to God and in the patience to accept suffering without the loss of faith.
