The most important things in the world [with regard to the subtle, incipient activation of things] are tendencies. Tendencies may be strong or weak. If a tendency is extremely strong, it cannot be controlled. But it is possible to control it quickly if one realizes that it is strong. To control it requires effort. If one does not realize early enough, it will not be easy to apply effort. If one has exerted his effort and does not succeed, that is due to Heaven, but if one either does not realize or does not apply effort, that is due to man. Is it due to Heaven? No, it is due to man. Why complain?

(Chow Tun-i)