Milton is one of the most solid staples of the English canon. He is best known for his Christian epic, Paradise Lost (1667). The epic explains the origin of evil and treats free will vs. predestination as well as political tyranny. Milton is also known for his defense of free expression in Areopagitica. Much of his time was spent promoting the Puritan cause. He was inspired not only by the Bible (Genesis, Job, and Psalms in particular) but also by classic authors including the epic poets Virgil and Homer.