Avidya is absence of Right Awareness. Through Avidya , man gets bound; so wisdom is the cure. That alone can take him across. (BSS, p. 93)
The root cause viz., Avidya (ignorance of our divine nature) leads to Ahamkar or rising of the ‘I’ – thought (identification with the body) which results in the birth of the mind (which consists of other thoughts or Sankalpas and Samskaras or Vasanas, predispositions). In other words, mind is nothing but a bundle of desires (Kama), which propels a man to do Karma (action). To experience the good and/or bad effects of Karma, the doer has to take another Janma (birth) after death of the present body. Then Janma is followed again by Karma provoked by Kama – this vicious circle goes on endlessly till the root-cause of Avidya is removed.
The cataract of the eye produced by the eye itself obstructs the vision of the eye; when the cataract is removed by surgery, the regains its lost vision. The moss arising out of water hides the water from view; when the moss is cleared off, water becomes visible. The ash produced by burning charcoal covers the fire itself, making it appear as cinder or ember; inside becomes exposed. The clouds caused by the sun hide the sun himself; when they are blown off by wind, the sun becomes visible. The rust produced by iron covers the iron itself, and is removed when burnt in fire. Likewise, Avidya or ignorance originates from Atma or true Self in the form of the false self and veils the Atma itself; when the Avidya is dispelled by Sadhana (spiritual discipline); the Self-effulgent Atma shines forth in all its brightness. (NNSG Vol.2, pp. 97-98)