TL;DR: Many models of the future exist. Several are relevant. Hyperbolic model is strongest, but too strange.
Our need: correct model of the future
Different people: different models = no communication.
Assumptions:
Model of the future = main driving force of historical process + graphic of changes
Model of the future determines global risks
The map: lists all main future models.
Structure: from fast growth – to slow growth models.
Pfd: http://immortality-roadmap.com/futuremodelseng.pdf
One of the proponents of spiral development was Karl Marx. He claimed that history will come to the same constructions but on the higher level of development. E.g. he claimed that primitive communism of tribal people will be reached again on the highest level of society development. He probably got the idea of spiral development from Hegel.
Spiral development is combination of idea of progress and idea of circularity of history.
About yangization... I think I have to update the link ))
If I remember my philosophy lessons in high-school, Hegel was the proponent of the idea that history faces moments where it develops a thesis, which eventually makes the opposite thesis grows, until finally the two are reunited in a synthesis. That is, a progression, circular in nature, but still expanding.
It's curious that the spiral in the picture grows inwards, not outwards. Weird.