We have recognized two distinct mental states—the conscious and the unconscious—and have found them constantly pressing each on the other’s domain. Our study of consciousness reveals the normal in the aspects of sleeping and waking, also various abnormal states. Consciousness may become excited, depressed, confused, delirious, or insane. We shall consider later some of the mental workings that account for these abnormal expressions. At present let us examine the mind’s activities in sleep and in delirium.
Consciousness in Sleep
Sleep seldom, if ever, is a condition of utter unconsciousness. We so frequently have at least a vague recollection, when we wake, of dreaming—whether or not we remember the dream material—that we are inclined to accept sleep as always a state of some kind of mental activity, though waking so often wipes the slate clean. A new word which serves our purpose well has come into common use these last years, and we describe sleep as a state of rest of the conscious mind made possible as weariness overpowers the censor, and this guard at the gate naps. The censor is merely that mental activity which forces the mind to keen, alert, constructive attention during our waking hours, a guard who censors whatever enters the conscious mind and compares it with reality, forcing back all that is not of immediate use, or that is undesirable, or that contradicts established modes of life or thought. In sleep we might say that the censor, wearied by long vigilance, presses all the material—constantly surging from the unconscious into consciousness, there to meet and establish relations with matter—back into the unconscious realms, and locks the door, and lies and slumbers. Then the half-thoughts, the disregarded material, the unfit, the unexpressed longings or fears, the forbidden thoughts; in fact, the whole accumulation of the disregarded or forgotten, good, bad, and indifferent—for the unconscious has no moral sense—seize their opportunity. The guard has refused to let them pass. He is now asleep. And the more insistent of them pick the lock and slip by, masquerading in false characters, and flit about the realms of the sleeping consciousness as ghosts in the shelter of darkness. If the guard half-wakes he sleepily sees only legitimate forms; for the dreams are well disguised. His waking makes them scurry back, sometimes leaving no trace of their lawless wanderings. So the unconscious thoughts of the day have become sleep-consciousness by play acting.
Consciousness in Delirium
At this time of our study it will suffice to say that in delirium and in insanity, which we might very broadly call a prolonged delirium, the toxic brain becomes a house in disorder. The censor is sick, and sequence and coherence are lost as the thronging thoughts of the unconscious mind press beyond the portals into consciousness, disordered and confused. We shall later find, however, that this very disorder falls into a sort of order of its own, and a dominant emotion of pain or ecstasy, of depression or fear, of exaltation or depreciation calls steadily upon the stored away incidents and remembered, related feelings of the past and interprets them as present reality. The censor of the sick brain is stupefied by toxins, shock, or exhaustion, and the citadel he is supposed to guard is thronged with besiegers from every side. The strongest—i. e., those equipped with most associations pertinent to the emotional status at the time—win out, occupy the brain by force, and demand recognition and expression from all the senses, deluding them by their guise of the reality of external matter.
We find consciousness, then, determined by all past experience, by an external world, and by its organ of expression—the brain.
Consequently, our psychology leads us into anatomy and physiology, which, probably, we have already fairly mastered. In rapid review, only, in the following chapter we shall consider the organs of man’s consciousness, the brain, spinal cord, and the senses, and try to establish some relation between the material body and its mighty propelling force—the mind.
CHAPTER III
ORGANS OF CONSCIOUSNESS
Nothing is known to us until it has been transmitted to the mind by the senses. The nerves of special sense, of sight, hearing, smell, taste, touch, the temperature sense (“hot or cold” sense), the muscular sense (sense of weight and position), these, and the nerves controlling voluntary motion, form the peripheral, or surface, nervous system. This acts as a connecting medium between the outside world and the central nervous system, which is composed of the brain and spinal cord. We might liken the nerves, singly, to wires, and all of them together to a system of wires. The things of the external world tap at the switchboard by using the organs of special sense; the nerves, acting as wires, transmit their messages; at the switchboard is the operator—consciousness—accepting and interpreting the jangle of calls.