《金剛經》以發揮空義著名，全經雖沒有一「空」字，但行文一氣呵成，皆在說空。本文指在透過經中的「四相否定」與「即非詭辭」兩種遮詮方式，來看般若思想言空的思考方式。四相否定是同時對我、人、眾生、壽者這四個面相的否定，以展示諸法的緣起性格，無自性可得，因而是空。即非詭辭是透過表面上是詭辭。實質上包含辯證成分的表述式，在正、反、合的思路中的「反」的步驟，否定諸法的自性，以成就空義。「即非」即是當體否定自性以顯空義之意。

　　　　　The Vajracchedlika-sutra is famous for its elaboration of the profoundmeaning of emptiness in Buddhist circle. Althrough the term "emptiness"or " Sunyata" does not appear in the text, its purpose of explicating thisdoctrine is undeniable. The present work is a study of two forms ofnegative expression representative in the text, in order to reveal thespecific way of thinking of the sutrs and the Prajnaparamita literature.They are the fourfold aspect negation and the immediate negationparadox. In the fourfold aspect negation, the subjects of the self, humansin general, sentient beings and whatever that maintains a persistentexistence, are simultaneously negated as being devoid of "self nature."Thereby the character of emptiness is revealed, whereas the immediatenegation paradox seems a paradox at first glance, but actually it carriesa dialectical thought process. In its second phase of antithesis, the " selfnature" usually ascribed to the entities or the phenomenal world isnegated. The meaning of emptiness is revealed right in this negation of"self nature." "Immediate negation" indicates the complete refutation of"self nature" right here and now.