一法中道 In Consciousness-only theory, the idea that each one of the three natures 三性 by itself contains the meaning of the middle path. That is, the nature according to 'all pervasive discrimination' is that "people exist" and "principle does not exist." In this, there is the middle path's meaning of "neither existent nor empty."
指於一法上論非有非空之中道妙理,乃法相宗所立中道之一義。與「三性對望中道」對稱。法相宗以遍計所執性為妄情,故判為空;以依他起性與圓成實性為假有與真有,故判為有。自此三性之對望而立之中道義,稱為三性對望中道。又此三性是一法上之三性,故此法為非有非空之中道。
然若詳論之,則三性中之每一性皆具有中道之義,即遍計所執性是情有理無,在妄情之上屬有,故非空;依理而言為無,故非有,是為非有非空之中道。依他起性於眾緣和合上為假之存在,故為假有實無。以其假有,故非空;以其實無,故非有,是為非有非空之中道。圓成實性遠離一切妄想而無相,故非有;然以其為真實如常之性,故非空,是為非有非空之中道。上述乃各就三性中之一性,立中道之義,稱為一法中道。或謂一法中道係依三性對望而立圓成實性之體,於依他起性之上成為一法,而於一色一香上談論中道之理。故百法問答抄卷八謂,三性對望中道之外,無一法中道之義。〔大乘法苑義林章卷一本、成唯識論同學鈔卷七之三〕(參閱「中道」1030)[1]