_Neurons in Psychic States_.--This same explanation would serve for narcosis, that is, for anesthesia, due to chloroform or ether, or any other drug. As a consequence of the effect of the narcotic upon the central neuron, they are brought into a condition resembling fatigue, at least to the extent of breaking their connections with other neurons so long as they are under the influence of the drug. While sensory nerves at the periphery, then, are being stimulated by the cutting of tissues to which they are attached, the message from them does not reach the brain because of a disturbance of the connections in the chain of neurons. Drunkenness illustrates the same phenomenon in a less degree. The effect of the intoxicant upon the central neurons disturbs sensation because it makes the connection much less complete than before, and so it is easy to understand the familiar occurrence of even severe injuries to drunken men without their being aware of them, or at least without their suffering nearly so much as would be the case if they were not intoxicated. _Hypnotism_.--The same theory would also hold for the phenomena observed in hypnotism. After all, the best explanation of hypnotism that we have is that there is a turning inward of the patient's attention, so that only those sensations are allowed to reach the brain to which mental attention has already been called by suggestion. Hypnotism usually begins with a certain fatigue of peripheral neurons until these do not act normally, and then the cerebral neurons become, as it were, short-circuited on themselves with a consequent internal concentration of attention. The anesthesia so often noted in hypnotic or hysterical states is explained by the same theory. For the time being, at least, the connection between the peripheral neurons and the central neurons is broken or but imperfectly made, and conduction does not take place, or is hampered. There may be loss of motion as well as of sensation, or of motion without sensation. In all these cases, the discontinuity of the nervous system enables us to understand more readily the mechanism by which these curious phenomena occur. Exaltation or intense interest or profound preoccupation may so concentrate nervous energy within the nerve centers themselves as to inhibit the flow of sensory impulses from without and thus enable {118} people to stand pain and fatigue that would otherwise seem quite unbearable.