When the mind is without care or joy, this is the height of Virtue. When it is unified and unchanging, this is the height of stillness. When it grates against nothing, this is the height of emptiness.
Zhuangzi posits ‘height’ as the superlative qualitative apex of inner cultivation, equating it with the culmination of Virtue, stillness, emptiness, and limpidity as states of perfected consciousness.
, The Complete Works of Zhuangzi, 2013thesis