The point was specifically intended to be as simple as possible, but this very simplicity is disturbing to the complicated intellectual mind. There is a particularly telling story of the exchange Chao-chou held with Nan-ch'uan concerning the Tao, meaning the way to enlightenment: _When Chao-chou asked his master, "What is the Tao?" the latter replied, "Tao is nothing else than the ordinary mind." "Is there any way to approach it?" pursued Chao-chou further. "Once you intend to approach it," said Nan-ch'uan, "you are on the wrong track." "Barring conscious intention," the disciple continued to inquire, "how can we attain to a knowledge of the Tao?" To this the master replied, "Tao belongs neither to knowledge nor to no-knowledge. For knowledge is but illusive perception, while no-knowledge is mere confusion. If you really attain true comprehension of the Tao, unshadowed by the slightest doubt, your vision will be like the infinite space, free of all limits and obstacles. Its truth or falsehood cannot be established artificially by external proofs." At these words Chao-chou came to an enlightenment. Only after this did he take his vows and become a professed monk.15 _ Nan-ch'uan's assertion that Tao is nothing else than the ordinary mind, but that it cannot be reached by deliberate searching, is the longstanding commonplace of Ch'an. However, he here adds an interesting new assertion: He claims here that although the person finding this enlightenment has no doubt of its reality, it cannot be proved or disproved by any objective tests. There is no way that the enlightened person can be shown objectively to have achieved his goal. The Ch'an masters could test enlightenment by matching the claimant's illogic against their own; if his "craziness" matched, then the disciple passed. But there is, by definition, no objective test of enlightenment. But then, how do you test the ultimate realization that there is nothing to realize other than what you knew all along? Quite simply, the master's intuition is the final authority. Their dialogues frequently were full of electricity, as witness another exchange that ended quite differently: _Chao-chou asked, "Tao is not external to things; the externality of things is not Tao. Then what is the Tao that is beyond things?" The master struck him. Thereupon Chao- chou took hold of the stick and said, "From now on, do not strike a man by mistake." The Master said, "We can easily differentiate between a dragon and a snake, but nobody can fool a Ch'an monk._"10_ _ Chao-chou here seems to be declaring to Nan-ch'uan that his enlightenment is genuine. And Nan-ch'uan, for his part, is asserting that the Master's judgment, not the monk's, is the final criterion. In another incident Chao-chou actually has the last word.