Excerpt from the original CRV Manual by Paul H. Smith:

Perceiving apprehending, or noticing with a degree of controlled thought or observation; recognizing as existent, factual, or true. Recognizing as factual or existent something external. Present especially to the senses. Involving rational power, perception, and awareness. By definition, the “conscious” part of the human being is that portion of the human consciousness which is linked most closely to and limited by the material world.