I found Western Classical Philosophy particularly Aristotle's Four Causes and his concept of the "unmoved mover", better translated as "unchanged changer", to be very useful in modeling wu wei.  There are passages in both the Neiye and the Dao De Jing that support this comparison, especially in regard to the notion of "the One".  I have posted on these ideas in several places, but if you are interested I can work up a post and some references for here.   ZYD