The instincts within the body create various desires; the so-called seven emotions and six desires all originate from the body. Without a strong will, one will sink into the spirit and let oneself float in the sea of one's desires.
The Taoist Family has methods to tame the Monkey Mind; the Buddhist Sect has ways to cut off the seven emotions and six desires, all to suppress the evil beasts within.
And only the Spirit can confront these desires, allowing one to find the true self in the increasingly materialistic world, thereby fully controlling one's body and actions; everything done is one's own choice.
This is the use of Spirit to harness the body.
In some ways, this true self state is what the Taoist Family refers to as jumping outside the Three Realms, not being within the five elements - the Spirit Realm.
Unaffected by external affairs or material things, everything is centered on controlling one's own will.
Ancient philosophies have extensively explained this realm.
