Ignorance is taking the impermanent for eternal, the impure for pure, pain for pleasure, and the non-Self for the Self.

This sutra defines avidyā through four fundamental confusions:

Confusing anitya (impermanent) with nitya (eternal): believing that possessions, relationships, or the body will last forever.

Confusing aśuci (impure) with śuci (pure): not perceiving the changing and composite nature of objects of desire.

Confusing duḥkha (pain) with sukha (pleasure): not seeing that all worldly pleasure contains the seed of suffering.

Confusing anātman (non-Self) with ātman (Self): identifying with body, mind, or emotions instead of pure consciousness.

These four inversions are the essence of spiritual ignorance.