A single supreme tattva exists; duality is superimposed upon it.

Ekam eva paraṃ tattvaṃ: This is the foundational phrase from the Chāndogya Upaniṣad (VI.2.1), sad eva saumyedam agra āsīt—in the beginning, only the Real existed. Vāsiṣṭha reframes this in the key of āropa (superimposition). There are not two realities; duality is āropita—projected, superimposed, like the snake upon the rope. This is crucial: it is not that duality is “bad” and must be eliminated. It is that it was never real; it only appeared to be real. The work of the sādhaka is not to reject duality—that would be aversion, dveṣa, another kleśa—but to see its nature as āropa. When the rope is seen, the snake is not “destroyed”; it simply ceases to be seen. So it is with duality: it is not destroyed, it ceases to be seen. The yogi does not hate the dualistic world; they use it as a means to remember unity. Every dual encounter—self-other, subject-object—is an opportunity for viveka (discernment). The practice is not one of escape; it is a transformation of vision.