While the Miltonic speaker promises to "justify the ways of God to men", the theodicy of Paradise Lost is repeatedly destabilized by competing powers in the narrative—grace and free will, hierarchy and equality, God's wrath and God's mercy, allowance and command, wisdom and temperance. While most discussions of Paradise Lost categorize the poem as heretical or orthodox, this thesis explores the poem's many sites of doctrinal indeterminacy. Chapter one surveys the differing accounts of free will, grace, and predestination contained in Milton's de doctrina christiana, Luther, and Erasmus. Chapter two argues that Satan's and Abdiel's opposed definitions of freedom and servitude figure the Arminian failure to navigate the infinite regress of grace and free will. Chapter three examines the dislocating biblical allusions in the first invocation revealing that the Spirit/Muse's instruction may be treacherous. Chapter four argues that Raphael's prescription of rational temperance and Adam's desire for unattainable knowledge are significantly antagonistic. Finally, these sites of indeterminacy mark the limitations of human rationality and Miltonic theodicy.