Sumerian dead dwelled in darkness feeding on dust and clay. If bodies were burned or left unburied on earth their souls would wander finding no peace. Proper burial rites and offerings were required to properly sustain the dead as in Egyptian culture. Children were deemed to be exempt from any suffering in the netherworld. In the netherworld, you wear garments of feathers and are presided over by a scribe, princes, and the gods of goddesses of that realm. There is no return to mortal life from there. In some visions or descents into the underworld there is a figure who intercedes on behalf of the newly dead against the wrath of the god of death.
The Egyptian dead underwent a judgment where their heart was weighed against a feather. The good would move on to the afterlife while the bad would be devoured (destroyed). The Egyptian soul had many parts. The Ka or life energy of the Egyptian is what carried on a shadowy existence in the underworld. It is what left the body at death and continued its existence in the underworld near to its body as long as it was nourished by the life energy of offerings of food and drink. The Akh or the "shining one" was pure intelligence, the true eternal and indestructible self that ascended to the sky after death. It was separate from the Ba and the Ren, the more temporal aspects of the human soul on earth.
Herodotus is called the Father of History for his being the first author to attribute earthly events to natural and rational causes rather than to the intervention of gods and goddesses. His "History of the Peloponnesian Wars" is also considered a landmark in the academic disciplines of international relations and political science.