The discussion of the stream and sequence effect is the core of the argument in WHEE. This post can set up a link for a discusssion later at The Gurdjieff Con.
The idea is simple but strange: the flow of history, the stream, is a continuous flow of events. But as we look closely we see an overlaid sequence effect in the form of discontinuous transitions, e.g. the Axial Age. And the modern transition. This is odd but it can be seen as an kind of ‘evolution on two levels’ and it is a way to set directionality in history. In a darwinian intellectual culture the idea will produce frowns, but it is effective in resolving a number of mysteries, not least the Axial Age and the rise of modernity. My favorite example is the way buddhism in India suddenly emerges from the ‘stream’ of proto-hinduism and generates a new era of spiritual history. WHEE has lot of examples. The idea was used more in the third edition and less used in the fourth: too confusing. But the idea is a key to how ‘evolution’ really works and is worth pursuing.