大乘起信論義疏 2.33

2.33

問曰：妄識若非意根，何故《楞伽》及此論中說為意乎？釋言：彼乃借名顯示，非即意根。如《楞伽》中說「第七識以之為心。」今此論中，宣說真識以之為心，豈可名同便是一物？心名雖同，真妄兩別；意名雖一，何妨差別。

Question: If deluded consciousness is not the mind-faculty, why is it called mentation (manas) in the Laṅkāvatāra [Sūtra] and in this treatise? Answer: That is merely borrowing the name to indicate it; it is not the mind-faculty itself. Just as in the Laṅkāvatāra [Sūtra] it says: 'The seventh consciousness is taken as mind (citta).' Now in this treatise, it is proclaimed that true consciousness is taken as mind (citta); how could identity of name make them the same thing? Although the name 'mind' is the same, the true and the deluded are two different things; although the name 'mentation' is one, what prevents them from being distinct?