How did the Book of Changes infer its essence?

You should have read the original book of changes. It mainly talks about the image of hexagrams. The crack on the tortoise shell after the ancients burned it is a divinatory symbol in the Book of Changes. The hexagrams are based on yin and yang gossip. The Book of Changes can actually be regarded as a math book that teaches you how to calculate hexagrams, and it can also be regarded as a translated book full of life philosophy. The thought of the Book of Changes is the golden mean.