"4. The darkness of unwisdom is the field of the others. These hindrances may be dormant, or worn thin, or suspended, or expanded. Here we have really two Sutras in one. The first has been explained already: in the darkness of unwisdom grow the parasites, hate, lust, attachment. They are all outgrowths of the self-absorption of the psychical self... they must be fought and conquered, or, as Patanjali quaintly says, they must be worn thin,-as a veil might, or the links of manacles."