Brahman — The Ultimate Reality, Ground of Being

Brahman is the ekam sat (one reality) of the Rigveda (1.164.46), the nirguna (without attributes) and saguna (with attributes) ground of all existence. The Taittiriya Upanishad (3.1) defines it as 'that from which beings are born, by which they live, and into which they dissolve.' Shankara's Advaita Vedanta establishes Brahman as the sole reality through the method of neti neti (not this, not this) — neither perceiver nor perceived, neither cause nor effect, but the substratum (adhishthana) upon which all nama-rupa (name and form) appears. The mahavakyas — 'Tat tvam asi' (Chandogya Upanishad 6.8.7), 'Aham Brahmasmi' (Brihadaranyaka Upanishad 1.4.10) — declare the identity of Atman and Brahman as the culminating insight of Vedantic inquiry.