Adhyāsa

Adhyāsa, “superimposition”, is the term with which Śaṅkara begins his commentary on the Brahma Sūtras. It names the appearance of something in a place where it is not: the snake seen in a coil of rope in poor light, or the silver seen in mother-of-pearl. What is superimposed is not simply nothing, since it is really experienced; nor is it real, since it vanishes when the ground is seen clearly.

Śaṅkara argues that the whole of ordinary experience rests on a mutual superimposition between the self and the not-self. The self, which is pure awareness, is taken to be the body and the mind, so that we say “I am tall” or “I am unhappy”; and the body and mind are taken to be conscious, borrowing the light of the self. Every practical activity, including ritual and the study of scripture itself, takes place within this superimposition.

The doctrine explains why, for Advaita, liberation comes by knowledge alone: one does not need to change the rope or destroy the snake, only to see what was always there. It also explains why the Upaniṣads teach by negation, removing what has been superimposed until only the self remains.