Despite developments in neuroscience, consciousness is unidentified in the brain. Moreover there is no scientific definition of what it is or does. This paper proposes that consciousness is not a scientific category. However, by 'postulating' consciousness as self-explanation, the brain can communicate with other brains in collective action. But the brain can generate a more plausible self-description as brainsign. There are two foundational tenets. (1) Brain-sign arises from the brain's interpretation of its causal orientation towards the world at each moment, and is 'apparent' as the world; and (2) It facilitates communication between brains about the world in collective action which is uncertain or imprecise. It is therefore grounded in the brain's bio-physical operation. Signs are ubiquitous bio-physical states, but they are not causal for the hosting organism. The paper contrasts brain-sign with consciousness both as theory, and in empirical findings. Brain-sign is the source of all theories, including itself.