One day Yao-shan Wei-yen (750-834), one of the well-known Chinese Ch'an master, was asked by the host of the monastery to give his sermon to the assembly who for a long while was expecting his teaching. Yao-shan said: "Strike the bell."
A novice was trying to fix a broken Lisp machine by turning the power off and on. Knight, seeing what the student was doing spoke sternly: "You can not fix a machine by just power-cycling it with no understanding of what is going wrong." Knight turned the machine off and on. The machine worked.