Fixing the White Horse Discourse: Zhuangzi’s Proof of “A White Horse Is not a Horse”

This article proposes an interpretation of Zhuangzi’s comment, in “Discussion on Making all Things Equal” (“Qiwulun” 齊物論), on the “White Horse Discourse” (“Baimalun” 白馬論) that suggests his awareness of what Western logicians call intuitionist proof. According to logical intuitionism, one cannot rely on the Law of the Excluded Middle, and relatedly the Law of Double Negation, to facilitate formal reasoning. Consequent to this prohibition is an asymmetry in proof: one may indirectly prove his or her denial of a statement p by deriving an absurdity from p, but there is no similar way to prove p from the assumption of not-p. It is argued here that in this intuitionist framework, Zhuangzi’s strategy is in effect a recipe for silencing a debater who challenges the acceptability (可) of the opponent’s beliefs. An account shall also be given of how to reconcile Zhuangzi’s relativism with his dialectical reasoning based on reductio ad absurdum (bei 悖).