सूक्तिकायां यथाऽज्ञानं रजतस्य यदात्मनि ।
कल्पितस्य निदान तत्तमः इत्यवगम्यते ॥ ८ ॥
Just as non-wisdom (makes) the mother-of-pearl (appear) as silver, what is the Self
Is fastened on a structure; thus this darkness becomes intelligible.
Commentary
Again the sage uses the time honoured example of the mother-of-pearl and silver illusion caused by ignorance, and goes on to say that when the Self is fastened on to a structure there is darkness. It is the mind playing around with concepts and word-magic, distorting the meaning of the Self, and erroneously fastening the Self on a structure. This is delusion.
The mind plays many tricks and it is sheer ignorance to think that the Self-Absolute can be structuralized. The Self is beyond all limitations and structures. As the sage declares, "thus this darkness becomes intelligible," when we understand the nature of the Self.
Sankaracharya defines darkness in his commentary on the Bhagavad Gita (XVIII.22) in this way: "The knowledge of darkness is engrossed in one single effect like the body or an external image. This knowledge is said to be darkness because of lack of discrimination."