Page "Lost Legacy" Paragraph 5

According to psychic records found by the good adepts, humanity reached a great level of development in a Golden Age, but when their leaders ( mythologized into such gods as Jove and Odin ) moved on to a new plane of existence, a new group used their mental powers for profit.

After a great war their main bases in Mu and Atlantis sank and humanity was thrown back to a Stone Age.