In Inferno, Charon objects to the presence of Dante on the bank of the river Acheron because he is not dead.
Charon, who is the ferryman of souls, meets Dante when he is entering Hell. Charon tries to force Dante to return where he came from since the living souls cannot cross the river Acheron, which is the last barrier to the entrance into the underworld ("Charon: And you approaching there, you living soul,/keep well away from these--they are the dead"). However, Virgil, who guides Dante through Hell, explains Charon that Dante's journey is willed by God.