首楞嚴義疏注經 3.277

3.277

此下同異俱非破也。此總問同異。識心，第八也。思量，第七也。了別，第六也。七八二識俱第六根，亦同名意，故此雙問二俱有過。

From here on refutes by showing that neither identity nor difference is tenable. This comprehensively asks about identity and difference. 'Conscious mind' is the eighth [consciousness]. 'Deliberative thoughts' is the seventh [consciousness]. 'Discernment' is the sixth [consciousness]. The seventh and eighth consciousnesses are both the faculty of the sixth, and are also both named mind; hence this double interrogation reveals faults in both.