Milton opens Paradise Lost by formally declaring his poem’s subject: humankind’s first act of disobedience toward God, and the consequences that followed from it. The act is Adam and Eve’s eating of the forbidden fruit of the Tree of Knowledge, as told in Genesis, the first book of the Bible. In the first line, Milton refers to the outcome of Adam and Eve’s sin as the “fruit” of the forbidden tree, punning on the actual apple and the figurative fruits of their actions. Milton asserts that this original sin brought death to human beings for the first time, causing us to lose our home in paradise until Jesus comes to restore humankind to its former position of purity.

Milton’s speaker invokes the muse, a mystical source of poetic inspiration, to sing about these subjects through him, but he makes it clear that he refers to a different muse from the muses who traditionally inspired classical poets by specifying that his muse inspired Moses to receive the Ten Commandments and write Genesis. Milton’s muse is the Holy Spirit, which inspired the Christian Bible, not one of the nine classical muses who reside on Mount Helicon—the “Aonian mount” of I.15. He says that his poem, like his muse, will fly above those of the Classical poets and accomplish things never attempted before, because his source of inspiration is greater than theirs. Then he invokes the Holy Spirit, asking it to fill him with knowledge of the beginning of the world, because the Holy Spirit was the active force in creating the universe.