Lewis ends the chapter by arguing that the personal heresy comes from an inability of most modern people to decide between a materialist and a spiritual theory of the universe. Either view would end the personal heresy. If the universe has a god behind it, then He speaks through the poet and it's not the poet only who speaks. If there is no god, there is no Muse who inspires the poet, and so there is nothing inside the head of the poet except a fortuitous concourse of atoms (25).