The key to the problem of consciousness is the question of its function. One source of information in this regard is the contrast between information that is and is not included within its compass. Consciousness presents us with a stable arena for our actions - the world - but excludes awareness of the multiple sensory and sensorimotor transformations through which the image of that world is extracted from the confounding influence of self-produced motion of multiple receptor arrays mounted on multi-jointed and swivelling body parts. Likewise excluded are the complex orchestrations of thousands of muscle movements routinely involved in the pursuit of our goals. In contrast to these exclusions, the contents that are included in consciousness, such as perceptual information at the level of objects and events, along with motivational, cognitive and mnemonic information, and their organization into a nested arrangement of external world, body and "self", suggests that consciousness arose as a solution to the logistics problems of decision making in mobile animals with complex, centralized brains, and has correspondingly ancient roots.