According to the ancients, the most entire sincere can foreknow. Happy and unlucky omens can be seen in the milfoil (yarrow stalks) and tortoise. Therefore the individual possess of the most complete sincerity is like a spirit (shen).
Happy and unlucky omens using the milfoil have been documented and passed down to posterity in the Zuozhuan. If Yi aficionados care to read and understand each of those ancient stories on yarrow stalks divination, they could gain a deeper insight on foreknowledge and the interpretation of oracles, because the Book of Changes actually spoke on each event.
When someone can divine with the milfoil and obtain happy or unlucky omens, that individual is said to possess of the most complete sincerity and is like a spirit. Perhaps the moniker of ‘Shen Suan’ or ‘Divine like a spirit’ was coined by later generations of Chinese because of this.
In Chapter Nine of the Great Treatise, after teaching how to obtain an oracle by using the milfoil or yarrow stalks, the wise wrote these:
It reveals Tao and renders nature and action divine. Therefore with its help we can meet everything in the right way, and with its help can even assist the gods themselves.
This section refers again to the Book of Changes in general. Its theme is that the book reveals the meaning of events in the universe and thereby imparts a divine mystery to the nature and action of the man who puts his trust in it, so that he is enabled to meet every event in the right way and even to aid the gods in governing the world. [W/B]
But first and foremost, Yi aficionados need to cultivate to become an earnest and sincere student. It can be a very lengthy process, for sincerity is a way of Heaven. And when the Yi speaks, you would know that the effort is very worth it.
Years later, you may realize that you can divine like a spirit (Shen Suan). However you may not be able to progress further reaching a dead end, so to speak.
That would be the time when you have to seek advice from the gods (include Daoist deities, heavenly immortals and Buddhas), if you have an affinity with them!
The Master said: Whoever knows the Tao of the changes and transformations, knows the action of the gods.