Throughout history, discussion between people about God has recurrently tended to focus on the question of whether God exists or is real. Some self-identify as "theists," from the Latin word for God, and assert the proposition that God does indeed exist. Others self-identify as "atheists," and assert the opposite. Yet a third long-standing camp self-identify as "agnostics," and claim not to know one way or the other. Yet just what is the very idea of God in the first place?