This is René Guénon’s most remarkable work, amongst many, for the utter clarity with which he develops his theme. His description of the descent from quality to quantity is set out in 40 chapters each building on what has been established before.
That we are living at the final end of the Great Cycle he had no doubt. Certainly his ideas have undermined my sense of ‘progress’ and ‘civilisation’ absorbed over many decades.
This is not an easy book to read because most chapters require careful consideration and concentration. But the ideas flow lucidly. By the end, the world you perceive when you finish the book is different to the one when you started. That is amazing.
His viewpoints on metals and money are quite revelatory. What would he have made of AI and cryptocurrencies? A step even deeper into a non-spiritual and therefore utterly transient illusion, I expect.
A must read for those who know the crucial importance of spiritual tradition.

Rene Guenon's master piece
Anyone that is interested in traditional doctrines and their place in the modern world needs to read this

Exceptional first half of the book viz. qualitative nature of space and time, the vector argument, etc. Also great discussion of the end-of-time singularity & relationship b/w space and time. Second half of the book is more esoteric and obscure w/ topics such as shamanism and dark magic, for which my modern mind was rather unprepared, discussed in great length.