Walter Cruttenden attempts to detail that Earth & it's inhabitants go trough a huge cycle, such as the 11 years Sun cycle. The cycle we humans go through, according to Walter, is about 24000 years.
As seen in the Chart below, the Iron age is the lowest level, meaning also, the lowest mental & intellectual capacity of human thinking & behavior. Apparently, you can match up this chart with the dark ages & as seen in the identification AD 2000, we are ascending to BRONZE Age, out of the IRON age. Also the book details the alignment of historic sites like the Pyramids in Egypt, etc. to show further evidence of past peoples leaving evidence of this flow of time & human growth & declines.