Wu wei is an important tenet of Taoism that involves knowing when to act and when not to act. Wu may be translated as not have; Wei (2nd tone) may be translated as do, act, serve as, govern. The literal meaning of Wu Wei is 'without action' and is often included in the paradox wei wu wei : 'action without action'. The pratice of wu wei and the efficacy of wei wu wei are fundamental tenets in Chinese thought and have been mostly emphasized by the Taoist school. The aim of wu wei is to achieve a state of perfect equilibrium, or alignment with the Tao, and, as a result, obtain an irresistible form of "soft and invisible power" over things (the self, others, a country). (see: Wikipedia)

 A key principle in realizing our oneness with the Tao is that of wu-wei, or "non-doing." Wu-wei refers to behavior that arises from a sense of oneself as connected to others and to one's environment. It is not motivated by a sense of separateness. It is action that is spontaneous and effortless. At the same time it is not to be considered inertia, laziness, or mere passivity. Rather, it is the experience of going with the grain or swimming with the current. Our contemporary expression, "going with the flow," is a direct expression of this fundamental Taoist principle, which in its most basic form refers to behavior occurring in response to the flow of the Tao. (from: ‘Taoism - The Wu-Wei Principle, Part 4’ by Ted Kardash)