Answer:
Neoconfucionismo
Step-by-step explanation:
Neo-Confucianism was a very popular philosophy during Song dysnastia, being widely referenced in all forms of art, including painting.
The blank space, purposely left by the artists in the paintings, referred to the metaphysical nature of neoconfucionism, since it encompassed the metaphysical freedom concept, capable of leading human thought to enlightenment and rational development, based on what actually exists, such as emptiness.