Learning the internal arts is a process that moves from the mind to the Qi to the body and back. This applies to all internal arts and is the foundation of Xingyi.
Thinking about a posture or movement helps understand it’s intent. This guides the Qi and consolidates structure and alignment. This is what the Chinese would call ‘Spirit’.
The shape of a posture or movement guides the Qi. Only through this direct experience is a deeper understanding obtained. This is what the Chinese would call ‘Essence’.

(Photo by John & Fish. Click image to see their Flickr page.)