Vedic & Upanishadic thought

What is the one reality behind everything, and what am I?

Late Vedic ritual specialists began asking what gave the sacrifice its power, and some teachers turned inward, linking the order of the cosmos to breath, mind and self. In the growing towns of the Ganges plain, where wandering renouncers questioned ritual, death, rebirth (saṃsāra) and release moved to the centre of thought.

Everything we see changes, so something must underlie the change; and the seer cannot itself be seen, so the self that knows is not any object it knows. If that knowing self is the very ground of the world, then grasping it ends the fear and bondage that come from mistaking oneself for a body.

1. Brahman is the single reality behind the many.
2. The self is not body or mind but their inner witness.
3. Knowledge, not ritual alone, liberates from rebirth.

The Upanishads became the scriptural foundation of Vedānta and set the shared vocabulary—self, karma, rebirth, liberation—that Buddhists and Jains also argued over.