The following is attributed to Zen master Ch’ing yuan Wei-hsin of the T’ang Dynasty: “Thirty years ago, before I started studying Zen, I said ‘Mountains are mountains, waters are waters.’ After I found insight as to the truth of Zen, I said ‘Mountains are not mountains, waters are not waters.’ But now, having achieved Satori, I say ‘Mountains are mountains, waters are waters.’

Paradoxical statements in esoteric words and sayings stem from the attempt to use common language to describe uncommon experience. They are not irrational. If we agree that mystical experience is an experience, then it should be possible to talk about it. Take this hypothetical example. There is an island where the inhabitants can only see in black and white, the traditional binary opposition. So, in their language ‘black’ and ‘non-white’ mean the same thing. With this, the language’s capacity for colors can be described as ‘something is either white or non-white’. Now, we have someone on the island that had a mystical experience and saw the color red. He tries to communicate this by saying he saw a thing that was neither white nor non-white. But to the typical inhabitant, this comes off as utter nonsense (BP). “This affirmative synthetic disjunction… consists of the erection of a paradoxical instance, an aleatory point with two uneven faces, which traverses the divergent series as divergent and causes them to resonate through their distance and in their distance. Thus the ideational center of convergence is by nature perpetually decentered, It serves only to affirm divergence, That is why it seemed that an esoteric ex-centric path was opened to us, a path altogether different from the ordinary one.” (Deleuze 175)

Some would object that there is no logical ground for mystical experience. However, technically speaking the statements of a mystic are founded in empirical observation of a trained consciousness. The fact that these experiences may be internal, does not make them inauthentic. It is rather a symptom of an ironic reversal which has taken place over the last century, as pointed out by Adorno in Minima Moralia. It used to be that objective knowledge, meant that which you saw and experienced directly first-hand. Now, objective is that which you believe because others have experienced and studied it for you, while subjective is the realm of faulty imperfect knowledge, somehow disconnected from the world.

“Esoteric language, which in each case represents the subversion, from the ground up, of the ideal language and the dissolution of the one who holds the real language” (Deleuze 140). It is the nature of esoteric words to disrupt the existing order, because that order is inherently man-made, imperfect and impermanent. The Zen master uses language to show and break its limits.

Gilles Deleuze, Logic of Sense
Henk Barendregt, Buddhist Phenomenology