There are, therefore, two distinct kinds or classes of cognitions: those stimulated or produced by external relations transferred into correlative internal relations within the brain through the organs of sense, that is, cognitions originating in energy transmitted by the organs of sense; and those stimulated or produced by internal relations already existing within the brain, which are records of previous cognitions, that is, cognitions originating in memory. But all cognitions are phenomena of brain activity.
The cognition of a flame of burning gas is an example of a phenomenon, the result of a certain change external to the brain, but capable of cognition through correlative internal relations produced in the brain through the organs of sense and only through those organs. A thought, desire or any cerebral act, state or condition, is a phenomenon, the result of a certain change within the brain and capable of cognition without the intervention of organs of sense. The brain may act, think, or will when all sight, hearing and other sensation is cut off, provided the brain has previously received and recorded cognitions of sensation.
Consciousness is the cognition or knowing of existence—the existence of self and of the Universe. The word, consciousness, defines not only the cerebral act of self-cognition, but also a cerebral condition or state, in which the brain has the power of producing other and different cognitions simultaneously with the cognition of existence. We shall also frequently refer to consciousness as the conscious state.
***Excerpt from Charles John Reed: The Law of Vital Infusion and the Phenomenon of Consciousness