Prajnanam Brahma — Consciousness Is Brahman
The Mahavakya 'Prajnanam Brahma' from the Aitareya Upanishad declares that pure consciousness (prajna) is identical with the ultimate reality (Brahman) — consciousness is not a product of the brain but the ground of all existence.
Prajnanam Brahma ('Consciousness is Brahman' — Aitareya Upanishad 3.3) is one of the four Mahavakyas (Great Declarations) of the Upanishads, assigned to the Rig Veda. Prajna means 'pure awareness, intelligence, consciousness' — the knowing quality itself, prior to any particular known content. Brahman is the ultimate reality. The identity declared by this Mahavakya is not that the brain produces consciousness but that consciousness IS the ultimate reality — matter and energy are appearances within consciousness, not consciousness a product of matter. This is the foundational claim of Advaita Vedanta: the universe is made of consciousness, not of matter. In the Aitareya Upanishad's context, consciousness is shown to be the source of all creation — 'In the beginning, the Atman (Self) alone existed. Nothing else winked. He created the worlds.' This consciousness-first ontology anticipates and challenges the dominant materialist assumption of modern science.
Prajnanam Brahma — Consciousness is Brahman.
Philosopher David Chalmers' 'Hard Problem of Consciousness' — the question of why and how physical processes give rise to subjective experience — is precisely the problem that Prajnanam Brahma resolves by inverting the question: consciousness doesn't arise from matter; matter (and all phenomena) arise within consciousness.
Aitareya Upanishad