Insofar as all thinking tends to alternate between "That's it" and "That's not", between assertion and negation, this type of critique tends to end up incorporating all conceptual thinking, including all that we usually identify as knowledge. This most general understanding is consistent with Buddhist emphasis on letting-go of all concepts and the Zhuangzi passages on mind-fasting, which negates such thinking. Yan Hui "expels knowledge" by learning to "just sit and forget" (ch. 6, 92), and Old Dan teaches Confucius to practice fasting and austerities to "smash to pieces your knowledge" (ch. 22, 132). Perhaps we can see how such a radical mental cleansing might also wash away the self, but what would that leave behind? Later we shall need to consider whether there is an alternative type of thinking which does not fixate on "That's it" and "That's not".

　　 Other important passages in the Zhuangzi relate "That's it" thinking with dividing up the world into things, for example:

[When a "That's it" which deems picks out things,] the Way interchanges them and deems them one. Their dividing is formation, their formation is dissolution; all things whether forming or dissolving in reverting interchange and are deemed to be one. Only the man who sees right through knows how to interchange and deem them one; the "That's it'" which deems he does not use, but finds for them lodging-places in the usual. The "usual" is the usable, the "usable" is the interchangeable, to see as "interchangeable" is to grasp; and once you grasp them you are almost there. The "That's it" which goes by circumstance comes to an end; and when it is at an end, that of which you do not know what is so of it you call the "Way". (ch. 2, pp. 53-54)

　　 Although our dualistic ways of thinking cause us to discriminate between things in the world and to see them as separate from each other, the Dao does not discriminate between things but treats them as a whole, for it transforms them into each other. The next sentence is more obscure: Burton Watson translates it as "Their dividedness is their completeness; their completeness is their impairment." This seems to be making a point consistent with the alternation of yin and yang in the I Ching: things take form (yang movement) by individuating, yet with the completion of that movement (e.g., maturity) the yang principle is fulfilled and begins to yield to yin dissolution; however, the Dao transforms them into each other, at whatever stage, because they are not separate from each other. Likewise, those who understand this clearly do not treat things as separate from each other. Such people are not trapped by discriminative concepts which fixate things into this or that, for their more fluid thinking is aware that such designations are always tentative, appropriate only for particular situations and purposes. Such tentative judgments are made because they are useful; realizing that judgments are to be made according to their usefulness frees one from rigid discriminations and enables us to perceive how things change into each other -- and to realize that is close to realizing the Dao. The discriminations which are made according to particular circumstances cease when those circumstances change; what remains then is the world experienced as it is before our conceptual thinking divides it up: what is called the Dao.

　　 According to this, the best judgments ("truths") are tentative because they are appropriate only for particular situations and different judgments are needed when those situations change. This perspective is expressed more clearly in the Liezi:

Nowhere is there a principle which is right in all circumstances or an action that is wrong in all circumstances. The method we use yesterday we may discard today and use again in the future; there are no fixed right and wrong to decide whether we use it or not. The capacity to pick times and snatch opportunities, and be never at a loss to answer events belongs to the wise.

　　 If ethical relativism means denying a fixed moral standard by which to evaluate situations, one could hardly find a better formulation; yet the last sentence seems to confuse the issue again, by emphasizing a distinction that most contemporary versions do not reserve a place for. There is an important difference between the sage and the rest of us. Evidently it is not enough to defend such a relativistic position, or to be a relativist in practice, for those philosophers who accept relativism do not thereby become wise, and those who live relativistically do not thereby live wisely. Mahayana Buddhism makes a similar point with its doctrine of upaya, the "skillful means" with which the bodhisattva works for the liberation of all sentient beings, adopting and adapting whatever devices are suitable to the immediate task at hand, disregarding conventional moral codes and even the Buddhist precepts when necessary. This type of relativism too is reserved for beings who have attained a high level of spiritual development -- the Buddhist equivalent of a Daoist sage.