大乘起信論裂網疏 3.55

3.55

Because the unshared ignorance of the seventh consciousness does not truly know the oneness of the true dharma, when it causes the minds and mental factors to operate in actual manifestation, it illusorily forms the two parts: perceiving and perceived. Furthermore, by the power of the seventh's two views of personal self and dharmic self, since it itself falsely clings to the perceiving part of the eighth as a real self and real dharma, forming defiled discrimination, and furthermore serves as the unshared intimate basis of the sixth consciousness, and the defiled and pure basis of the first five consciousnesses, causing the prior six consciousnesses to discriminate the various differentiated dharmas of defilement and purity, this seventh is therefore directly named the 'knowing consciousness'. If one contemplates that discrimination and what is discriminated are both devoid of intrinsic nature, then knowledge is without the mark of knowledge, and one then attains entry into the aspect of tathatā.