Souls are punished when they have gone forth from the body, some wandering among us, some going to hot or cold places of the earth, some harassed by spirits. Under all circumstances they suffer with the irrational part of their nature, with which they also sinned. For its sake there subsists that shadowy body which is seen about graves, especially the graves of evil livers.

XIX. Why sinners are not punished at once. - On the Gods and the Cosmos