People have believed in something like purgatory for thousands of years. Their specific ideas reflect their cultural environments and their personal feelings about the human condition. By looking at the dream vision genre over the past 2,000 years we may get a better idea of the development of the doctrine of purgatory and, with it, how people have understood themselves in history.
Douglass, Tucker, "Dream Visions as a Safe Space for Purgatorial Speculation" (2020). History Class Publications. 59.