Chapter II: Part 2

If we believe that, in accordance with the law of phylogenetic association, a continuous stimulation of both the brain and the thyroid gland, accelerated by summation, plays a role in the establishment of the pathologic interaction seen in Graves' disease, then it is but the next step to assume that if the nerve connection between the brain and the thyroid be severed, or if the lobe be excised and the patient reinforced by a sojourn in a sanatorium or in some environment free from former noci-associations, he may be restored to normal health, provided that the brain-cells, the heart, or other essential organs have not suffered irreparable damage. There are still many missing links in the solution of this problem, and the foregoing hypotheses are not offered as final, although from the viewpoint of the surgeon many of the phenomena of this disease are explicable.

Sexual-Neurasthenia

The state of sexual neurasthenia is in many respects analogous to that of Graves' disease. In the sexual reflexes, summation leads to a hyperexcitability by psychic and mechanical stimuli of a specific type which is analogous to the hyperexcitability in Graves' disease under trauma and fear; the explanation of both conditions is based on the laws of the discharge of energy by phylogenetic association and summation. It would be interesting to observe the effect of interrupting the nerve impulses from the field of the sexual receptors by injections of alcohol, or by other agencies, so as to exclude the associational stimuli until the nervous mechanism has again become restored to its normal condition. Interpretation of Some of the Phenomena of Certain Diseases of the Abdomen in Accordance with the Hypothesis of Phylogenetic Association

The law of phylogenetic association seems to explain many of the phenomena of certain lesions in the abdominal cavity. The nociceptors in the abdomen, like nociceptors elsewhere, have been established as a result of some kind of injury to which during vast periods of time this region has been frequently exposed. On this premise, we should at once conclude that there are no nociceptors for heat within the abdomen because, during countless years, the intra-abdominal region never came into contact with heat. That this inference is correct is shown by the fact that the application of a thermocautery to the intestines when completing a colostomy in a conscious patient is absolutely painless. One would conclude also that there are no touch receptors in the abdominal viscera, and therefore no sense of touch in the peritoneum. Just as the larynx, the ear, the nose, the sole of the foot, and the skin have all developed the specific type of nociceptors which are adapted for their specific protective purposes, and which, when adequately stimulated, respond in a specific manner in accordance with the law of phylogenetic association, so, the abdominal viscera have developed equally specific nociceptors as a protection against specific nocuous influences. The principal harmful influences to which the abdominal viscera have been exposed during vast periods of time are deep tearing injuries by teeth and claws in the innumerable struggles of our progenitors with each other and with their enemies (Fig. 9); peritonitis caused by perforations of the intestinal tract from ulcers, injuries, appendicitis, gall-stones, etc.; and overdistention of the hollow viscera by various forms of obstruction. Whatever may be the explanation, it is a fact that the type of trauma which results from fighting corresponds closely with that which causes the most shock in the experimental laboratory. Division of the intestines with a sharp knife causes no pain, but pulling on the mesentery elicits pain. Ligating the stump of the appendix causes sharp, cramp-like pains. Sharp division of the gall-bladder causes no pain, but distention, which is the gall-bladder's most common pathologic state, produces pain. Distention of the intestine causes great pain, but sharp cutting or burning causes none. In the abdominal viscera, as in the superficial parts, nociceptors have presumably been developed by specific harmful influences and each nociceptor is open to stimulation only by a stimulus of the particular type that produced it.

As a result of the excitation of nociceptors, with which pain is associated, the routine functions, such as peristalsis, secretion, and absorption are dispossessed from the control of their respective nervous mechanisms, just as they are inhibited by fear. This hypothesis explains the loss of weight, the lassitude, the indigestion, the constipation, and the many alterations in the functions of the various glands and organs of the digestive system in chronic appendicitis. It readily explains also the extraordinary improvement in the digestive functions and the general health which follows the removal of an appendix which is so slightly altered physically that only the clinical results could persuade one that this slight change could be an adequate cause for such far-reaching and important symptoms. This hypothesis explains certain gall-bladder phenomena likewise,-- indigestion, loss of weight, disturbed functions, etc.,--and it may supply the explanation of the disturbance caused by an active anal fissure, which is a potent noci-associator, and the consequent disproportionate relief after the trivial operation for its cure. Noci-association would well explain also the great functional disturbances of the viscera which immediately follow abdominal operations.

Postoperative and traumatic neuroses are at once explained on the ground of noci-association, the resulting strain from which, upon the brain-cells, causes in them physical lesions. If one were placed against a wall and were looking into the gun muzzles of a squad of soldiers, and were told that there were nine chances out of ten that he would not be killed outright when the volley was fired, would it help him to be told that he must not be afraid? Such an experience would be written indelibly on his brain. This corresponds closely to the position in which some surgical patients are placed. In railway wrecks, we can readily understand the striking difference between the after-effects in the passengers who were conscious at the time of the accident and those who were asleep or drunk. In the latter the noci-perceptors and receptors were not aroused, hence their immunity to the nervous shock. In the functional disturbances of the pelvic organs, association and summation may play a large role. On this hypothesis many cases of neurasthenia may well be explained. From the behavior of the individual as a whole we may well conclude that summation is but a scientific expression for "nagging." Many other pathologic phenomena may be explained in a similar manner. Thus we can understand the variations in the gastric analyses in a timid patient alarmed over his condition and afraid of the hospital. He is integrated by fear, and as fear takes precedence over all other impulses, no organ functionates normally. For the same reason, one sees animals in captivity pine away under the dominance of fear. The exposure of a sensitive brain to the naked possibility of death from a surgical operation may be compared to uncovering a photographic plate in the bright sunlight to inspect it before putting it in the camera. This principle explains, too, the physical influence of the physician or surgeon, who, by his PERSONALITY, inspires, like a Kocher, absolute confidence in his patient. The brain, through its power of phylogenetic association, controls many processes that have wholly escaped from the notice of the "practical man." It is in accordance with the law of association that a flower, a word, a touch, a cool breeze, or even the thought of a fishing rod or of a gun, is helpful. On the contrary, all suggestions of despair or misfortune-- a corrugated brow, the gloomy silence of despair, or a doubtful word-- are equally depressing. In like manner, one could add many illustrations of the symbolism that governs our daily lives. Thus we see that through the laws of inheritance and noci-association, we are able to read a new meaning into the clinical phenomena of various diseases.

Observations on Patients whose Associational Centers are Dulled, and on Diseases and Injuries of Regions not Endowed with Nociceptors

Reversing the order of our reasoning, let us now glance at the patient who is unconscious and who, therefore, has lost much of the power of association. His mouth is usually dry, the digestive processes are at a low ebb, the aroma of food causes no secretion of saliva, tickling the nose causes no sneezing; he catches no cold. The laryngeal reflex is lost and food may be quietly inhaled; the entire process of metabolism is low. The contrast between a man whose associational centers are keen and a man in whom these centers are dulled or lost is the contrast between life and death.

In accordance with the law of adaptation through natural selection, phylogeny, and association, one would expect no pain in abscess of the brain, in abscess of the liver, in pylephlebitis, in infection of the hepatic vessels, in endocarditis. This law explains why there are no nociceptors for cancer, while there are active nociceptors for the acute infections. It is because nature has no helpful response to offer against cancer, while in certain of the acute pyogenic infections the nociceptors force the beneficent physiologic rest.

Could we dispossess ourselves of the shackles of psychology, forget its confusing nomenclature, and view the human brain, as Sherrington has said, "as the organ of, and for the adaptation of nervous reaction," many clinical phenomena would appear in a clearer light.

Natural Selection and Chemical Noci-association in the Infections

Thus far we have considered the behavior of the individual as a whole in his response to a certain type of noci-influences. We have been voicing our argument in terms of physical escape from GROSS physical dangers, or of grappling with GROSS NERVE-MUSCULAR enemies of the same or of other species. To explain these phenomena we have invoked the aid of the laws of natural selection and phylogenetic association. If our conclusions be correct, then it should follow that in the same laws we may find the explanation of immunity, which, of course, means a defensive response to our MICROSCOPIC enemies. There should be no more difficulty in evolving an efficient army of phagocytes by natural selection, or in developing specific chemical reactions against _*microscopic enemies_, than there was in evolving the various nociceptors for our nerve-muscular defense against our _*gross enemies_. That immunity is a chemical reaction is no argument against the application of the law of natural selection or of association. What essential difference is there between the chemical defense of the skunk against its NERVE-MUSCULAR enemies and its chemical defense (immunity) against its MICROSCOPIC ENEMIES?

The administration of vaccines becomes the adequate stimulus which awakens phylogenetic association of a chemical nature as a result of which immune bodies are produced.

In discussing this subject I will raise only the question whether or not the specific character of the inaugural symptoms of some infectious diseases may be due to phylogenetic association. These inaugural symptoms are measurably a recapitulation of the leading phenomena of the disease in its completed clinical picture. Thus, the furious initiative symptoms of pneumonia, of peritonitis, or erysipelas, of the exanthemata, are exaggerations of phenomena which are analogous to the phenomena accompanying physical injury and fear of physical violence. Just as the acute phenomena of fear, or those which accompany the adequate stimulation of nociceptors, are recapitulations of phylogenetic struggles, so may the inaugural symptoms of an infection be a similar phylogenetic recapitulation of the course of the disease. A certain amount of negative evidence is supplied by a comparison of the response to a dose of toxins with the response to a dose of a standard drug. No drug in therapeutic dosage except the iodin compounds causes a febrile response; no drug causes a chill; on the other hand, all specific toxins cause febrile responses and many cause chills. If a species of animal had been poisoned by a drug during vast periods of time, and if natural selection had successfully established a self-defensive response, then the administration of that drug would cause a noci-association (chemical), and a specific reaction analogous to that following the administration of Coley's toxins might be expected. Bacterial noci-association probably operates through the same law as that through which physical noci-association operates. Natural selection is impartial, however. It must be supposed that it acts impartially upon the microscopic invader and upon the host. On this ground one must infer that, in accordance with the same law of natural selection, the bacteria of acute infections have met by natural selection each advance in the struggle of the host for immunity. Hence the fast and furious struggle between man and his microscopic enemies merely indicates to what extent natural selection has developed the ATTACK and the DEFENSE respectively. This struggle is analogous to the quick and decisive battles of the carnivora when fighting among themselves or when contending against their ancient enemies. But when phylogenetically strange animals meet each other, they do not understand how to conduct a fight: natural selection has not had the opportunity of teaching them. The acute infections have the characteristics of being ancient enemies. On this hypothesis one can understand the high mortality of measles when it is introduced into a new country. By natural selection, measles has become a powerful enemy of the human race, and a race to which this infection is newly introduced has not had the advantage of building up a defense against it by the law of natural selection. May not the phenomena of anaphylaxis be studied on associational lines? Then, too, there may be chemical noci-associations with enemies now extinct, which, like the ticklish points, may still be active on adequate stimulation. This brief reference to the possible relation of the phenomena of the acute infections to the laws of natural selection and of specific chemical noci-association has been made as a suggestion. Since the doctrine of evolution explains all or nothing, I have included many phenomena to see how reasonable or unreasonable such an explanation might be.

Recapitulation

The following are the principal points presented: In operations under inhalation anesthesia the nerve impulses from the trauma reach every part of the brain--the cerebrum that is apparently anesthetized as well as the medulla that is known to remain awake-- the proof being the PHYSIOLOGIC exhaustion of and the PATHOLOGIC change in the nerve-cells. Under ether anesthesia the damage to the nerve-cells is at least four times greater than under nitrous oxid. Inhalation anesthesia is, therefore, but a veneer-- a mask that "covers the deep suffering of the patient." The cause of the exhaustion of the brain is the discharge of nervous energy in a futile effort to energize the paralyzed muscles in an attempt to escape from the injury just as if no anesthetic had been given. The exhaustion is, therefore, of the same nature as that from overexertion, but if the nerve-paths connecting the field of operation and the brain be blocked, then there is no discharge of nervous energy from the trauma, and consequently there is no exhaustion, however severe or prolonged the operation may be.

Fear is a factor in many injuries and operations. The phenomena of fear probably are exhibited only by animals whose natural defense is nerve-muscular. The skunk, the porcupine, the turtle, have little or no fear. Fear is born of the innumerable injuries which have been inflicted in the course of evolution. Fear, like trauma, may cause physiologic exhaustion of and morphologic changes in the brain-cells. The representation of injury, which is fear, being elicited by phylogenetic association, may be prevented by the exclusion of the noci-association or by the administration of drugs like morphin and scopolamin, which so impair the associational function of the brain-cells that immunity to fear is established. Animals whose natural defense is in muscular exertion, among which is man, may have their dischargeable nervous energy exhausted by fear alone, or by trauma alone, but most effectively by the combination of both. What is the mechanism of this discharge of energy? It is the adequate stimulation of the nociceptors and the physiologic response for the purpose of self-preservation. According to Sherrington, the nervous system responds in action as a whole and to but one stimulus at a time. The integration of the individual as a whole occurs not alone in injury and fear, but also, though not so markedly, as a result of other phylogenetic associations, such as those of the chase and procreation. When adequate stimuli are repeated with such rapidity that the new stimulus is received before the effect of the previous one has worn off, a higher maximum effect is produced than is possible under a single stimulus, however powerful.

Sexual receptors are implanted in the body by natural selection, and the adequate stimuli excite the nerve-muscular reactions of conjugation in a manner analogous to the action of the adequate stimuli of the nociceptors. The specific response of either the sexual receptors or the nociceptors is at the expense of the total amount of nervous energy available at the moment. Likewise in daily labor, which, in the language of evolution, is the chase, nervous energy is expended. Under the dominance of fear or injury, however, the integration is most nearly absolute and probably every expenditure of nervous energy which is not required for efforts toward self-preservation is arrested; hence fear and injury drain the cup of energy to the dregs. This is the potential difference between fear and desire, between injury and conjugation.

What is the practical application of this? In operative surgery there is introduced a new principle, which removes from surgery much of the immediate risk from its trauma by establishing ANOCI-ASSOCIATION; it places certain of the phenomena of fear on a physical basis; it explains to us the physical basis for the impairment of the entire individual under worry or misfortune; it makes evident the physical results of the daily noci-associations experienced by the individual as a social unit. On the other hand, it explains the power of therapeutic suggestion and of other influences which serve for the time to change the noci-integration; it shows the physical basis for the difference between hope and despair; it explains some of the phenomena of Graves' disease, of sexual neurasthenia, possibly of hay-fever and of the common cold. The principle is probably equally applicable to the acute infections, in each of which chemical noci-association gives rise to many of the phenomena of the disease and it explains their cure by natural immunity and by vaccines. This hypothesis should teach us to view our patients as a whole; and especially should it teach the surgeon gentleness. It should teach us that there is something more in surgery than mechanics, and something more in medicine than physical diagnosis and drugs.

Conclusion

The brain-cells have existed for eons and, amid the vicissitudes of change, they have persisted with perhaps less alteration than has the crust of the earth. Whether in man or in the lower animals, they are related to and obey the same general biologic laws, thus being bound to the entire past and performing their function in accordance with the law of phylogenetic association.

For so long a time have we directed our attention to tumors, infections, and injuries that we have not sufficiently considered the vital force itself. We have viewed each anatomic and pathologic part as an entity and man as an isolated phenomenon in nature. May we not find in the laws of adaptation under natural selection, and of phylogenetic association, the master key that will disclose to us the explanation of many pathologic phenomena as they have already explained many normal phenomena?

And may medicine not correlate the pathologic phenomena of the sick man with the forces of evolution, as the naturalists have correlated the phenomena of the sound man, and thus may not disease, as well as health, be given its evolutionary setting?

PHYLOGENETIC ASSOCIATION IN RELATION TO THE EMOTIONS[*]

[*] Address before the American Philosophical Society, Philadelphia, April 22, 1911.

The surgeon is familiar with the manifestations of every variety of the human emotions in the various stations of life, from infancy to senility, in health and in disease. Not only does he come into intimate contact with the emotions displayed by the victims of disease and of accidents, but he also observes those manifested by the relatives and friends of the families of his patients. Moreover, he is unhappily forced to notice the emotional effect upon himself when he is waging an unequal battle against death-- the strain and worry at a crisis, when a life is in the balance and a single false move may be fatal, is an experience known only to the operating surgeon.

For the data for this paper, therefore, in which I shall for the most part limit my discussion to the strongest of all emotions--FEAR--I have drawn largely from my personal experience as a surgeon, as well as from an experimental research in which I have had the valuable assistance of my associates, Dr. H. G. Sloan, Dr. J. B. Austin, and Dr. M. L. Menten.

I believe it can be shown that it is possible to elicit the emotion of fear only in those animals that utilize a motor mechanism in defense against danger or in escape from it. For example, the defense of the skunk is a diabolic odor which repels its enemies; the skunk has no adequate equipment for defense or escape by muscular exertion, and the skunk therefore shows little or no fear. Again, certain species of snakes are protected by venom; they possess no other means of defense nor have they adequate motor mechanisms for escape and they show no fear. Because of their strength other animals, such as the lion, the grizzly bear, and the elephant, show but little fear (Fig. 6). Animals which have an armored protection, such as the turtle, show little fear. It is, therefore, obvious that fear is not universal and that the emotion of fear is felt only by those animals whose self-preservation is dependent upon an uncertain adequacy of their power of muscular exertion either for defense or for flight (Fig. 7).

What are the principal phenomena of fear? They are palpitation of the heart, acceleration of the rate and alteration of the rhythm of the respiration, cold sweat, rise in body temperature, tremor, pallor, erection of the hair, suspension of the principal functions of digestion, muscular relaxation, and staring of the eyes (Fig. 12). The functions of the brain are wholly suspended except those which relate to the self-protective response against the feared object. Neither the brain nor any other organ of the body can respond to any other lesser stimulus during the dominance of fear.

From these premises it would appear that under the influence of fear, most, perhaps all, of the organs of the body are divided sharply into two classes: First, those that are stimulated, and, second, those that are inhibited. Those that are stimulated are the entire muscular system, the vasomotor and locomotor systems, the senses of perception, the respiration, the mechanism for erecting the hair, the sweat-glands, the thyroid gland, the adrenal gland (Cannon), and the special senses. On the other hand, all the digestive and procreative functions are inhibited. What is the significance of this stimulation of some and inhibition of other organs? As far as we know, the stimulated organs increase the efficiency of the animal for fight or for flight. It is through skeletal muscles that the physical attack or escape is effected; these muscles alone energize the claws, the teeth, the hoofs, and the means for flight. The increased action of the muscles of the heart and the blood-vessels increases the efficiency of the circulation; the secretion of the adrenal gland causes a rise in the blood-pressure; the increased action of the thyroid gland causes an increased metabolic activity; there is evidence that glycogen is actively called out, this being the most immediately available substance for the production of energy; the increased activity of the respiration is needed to supply the greater need of oxygen and the elimination of the increased amount of waste products; the dilatation of the nostrils affords a freer intake of air; the increased activity of the sweat-glands is needed to regulate the temperature of the body which the increased metabolism causes to rise. The activity of all the organs of perception--sight, hearing, smell-- is increased in order that the danger may be more accurately perceived. It cannot be a mere coincidence that the organs and the tissues that are stimulated in the emotion of fear are precisely those that are actually utilized in a physical struggle for self-preservation.

Are any other organs stimulated by fear except those that can or that do assist in making a defensive struggle? I know of none. On the other hand, if an animal could dispense with his bulky digestive organs, whose functions are suspended by fear, if he could, so to speak, clear his decks for battle, it would be to his advantage. Although the marvelous versatility of natural selection apparently could devise no means of affording this advantage, it nevertheless shut off the nervous current and saved the vital force which is ordinarily consumed by these non-combatants in the performance of their functions. Whatever may be the origin of fear, its phenomena are due to a stimulation of all the organs and tissues that add to the efficiency of the physical struggle for self-preservation and an inhibition of the func-

{illust. caption = FIG. 19--THE BROAD JUMP. Note the similarity of the expression to the facial expression of fear and of anger (Figs. 12 and 21). (Wm. J. Brownlow, drawn from photo.) tions of the leading organs that do not participate in that struggle-- the non-combatants, so to speak. Fear arose from injury, and is one of the oldest and surely the strongest emotion. By the slow process of vast empiricism nature has evolved the wonderful defensive motor me-chanism of many animals and of man. The stimulation of this mechanism leading to a physical struggle is action, and the stimulation of this mechanism without action is emotion. We may say, therefore, that fear is a PHYLOGENETIC FIGHT OR FLIGHT (Fig. 18). On this hypothesis all the organs and parts {illust. caption = FIG. 20.-FINISH OF RELAY RACE.

Compare the facial expression of the runners with those in Figs. 12, 19, 22. These pictures illustrate the fact that the same mechanism is stimulated in emotion as in physical action. (Photo by Underwood and Underwood, N. Y.)}

of the body are integrated, connected, or correlated for the self-preservation of the individual by the activity of his motor mechanism (Figs. 12, 19, and 20). We fear not in our hearts alone, not in our brains alone, not in our viscera alone--fear influences every organ and tissue; each organ or tissue is stimulated or inhibited according to its use or hindrance in the physical struggle for existence. By thus concentrating all or most of the nerve force on the nerve-muscular mechanism for defense, a greater physical power is developed. Hence it is that under the stimulus of fear animals are able to perform preternatural feats of strength. For the same reason, the exhaustion following fear will be increased as the powerful stimulus of fear drains the cup of nervous energy even though no visible action may result. An animal under the stimulus of fear may be likened to an automobile with the clutch thrown out but whose engine is racing at full speed. The gasoline is being consumed, the machinery is being worn, but the machine as a whole does not move, though the power of its engine may cause it to tremble.

When this conception is applied to the human beings of today, certain mysterious phenomena are at once elucidated. It must be borne in mind that man has not been presented with any new organs to meet the requirements of his present state of civilization; indeed, not only does he possess organs of the same type as those of his savage fellows, but of the same type also as those possessed by the lower animals even. In fact, man has reached his present status of civilization with the primary equipment of brutish organs. Perhaps the most striking difference between man and animals lies in the greater control which man has gained over his primitive instinctive reactions. As compared with the entire duration of organic evolution, man came down from his arboreal abode and assumed his new role of increased domination over the physical world but a moment ago. And now, though sitting at his desk in command of the complicated machinery of civilization, when he fears a business catastrophe his fear is manifested in the terms of his ancestral physical battle in the struggle for existence. He cannot fear intellectually, he cannot fear dispassionately, he fears with all his organs, and the same organs are stimulated and inhibited as if, instead of it being a battle of credit, of position, or of honor, it were a physical battle with teeth and claws. Whether the cause of acute fear be moral, financial, social, or stage fright, the heart beats wildly, the respirations are accelerated, perspiration is increased, there are pallor, trembling, indigestion, dry mouth, etc. The phenomena are those which accompany physical exertion in self-defense or escape. There is not one group of phenomena for the acute fear of the president of a bank in a financial crash and another for the hitherto trusted official who suddenly and unexpectedly faces the imminent probability of the penitentiary; or one for a patient who unexpectedly finds he has a cancer and another for the hunter when he shoots his first big game. Nature has but one means of response to fear, and whatever its cause the phenomena are always the same--always physical.

If the stimulus of fear be repeated from day to day, whether in the case of a mother anxious on account of the illness of a child; a business man struggling against failure; a politician under contest for appointment; a broker in the daily hazard of his fortune; litigants in legal battle, or a jealous lover who fears a rival; the countless real as well as the baseless fears in daily life, in fact, all forms of fear, as it seems to me, express themselves in like terms of ancestral physical contests. On this law, fear dominates the various organs and parts of the body.

Anger and fear express opposite emotional states. Fear is the expression of a strong desire to escape from danger; anger, of a strong desire to attack physically and to vanquish opposition. This hypothesis is strongly supported by the outward expressions of fear and of anger. When the business man is conducting a struggle for existence against his rivals, and when the contest is at its height, he may clench his fists, pound the table, perhaps show his teeth, and exhibit every expression of physical combat. Fixing the jaw and showing the teeth in anger merely emphasize the remarkable tenacity of phylogeny. Although the development of the wonderful efficiency of the hands has led to a modification of the once powerful canines of our progenitors, the ancestral use of the teeth for attack and defense is attested in the display of anger. In all stations of life differences of opinion may lead to argument and argument to physical combats, even to the point of killing. The physical violence of the savage and of the brute still lies surprisingly near the surface (Fig. 21).

We have now presented some of the reasons based largely on gross animal behavior why fear is to be regarded as a response to phylogenetic association with physical danger. In further support of this hypothesis, I shall now present some clinical and experimental evidence. Although there is not convincing proof, yet there is evidence that the effect of the stimulus of fear upon the body when unaccompanied by physical activity is more injurious than is an actual physical contest which results in fatigue without gross physical injury. It is well known that the soldier who, while under fire, waits in vain for orders to charge, suffers more than the soldier who flings himself into the fray; and that a wild animal endeavoring to avoid capture suffers less than one cowering in captivity. An unexpressed smouldering emotion is measurably relieved by action. It is probable that the various energizing substances needed in physical combat, such as the secretions of the thyroid, the adrenals (Cannon), etc., may cause physical injury to the body when they are not consumed by action (Fig. 22).

That the brain is definitely influenced--damaged even-- by fear has been proved by the following experiments: Rabbits were frightened by a dog but were neither injured nor chased. After various periods of time the animals were killed and their brain-cells compared with the brain-cells of normal animals-- wide-spread changes were seen (Fig. 13). The principal clinical phenomena expressed by the rabbit were rapid heart, accelerated respiration, prostration, tremors, and a rise in temperature. The dog showed similar phenomena, excepting that, instead of such muscular relaxation as was shown by the rabbit, it exhibited aggressive muscular action. Both the dog and the rabbit were exhausted but, although the dog exerted himself actively and the rabbit remained physically passive, the rabbit was much more exhausted.

Further observations were made upon the brain of a fox which had been chased for two hours by members of a hunt club, and had been finally overtaken by the hounds and killed. Most of the brain-cells of this fox, as compared with those of a normal fox, showed extensive physical changes (Fig. 4).

The next line of evidence is offered with some reservation, but it has seemed to me to be more than mere idle speculation. It relates to the phenomena of one of the most interesting diseases in the entire category of human ailments--I refer to exophthalmic goiter, or Graves' disease, a disease primarily involving the emotions. This disease is frequently the direct sequence of severe mental shock or of a long and intensely worrying strain. The following case is typical: A broker was in his usual health up to the panic of 1907; during this panic his fortune and that of others were for almost a year in jeopardy, failure finally occurring. During this heavy strain he became increasingly nervous and by imperceptible degrees there developed a pulsating enlargement of the thyroid gland, an increased prominence of the eyes, marked increase in perspiration--profuse sweating even--palpitation of the heart, increased respiration with frequent sighing, increase in blood-pressure; there were tremor of many muscles, rapid loss of weight and strength, frequent gastro-intestinal disturbances, loss of normal control of his emotions, and marked impairment of his mental faculties. He was as completely broken in health as in fortune. These phenomena resembled closely those of fear and followed in the wake of a strain which was due to fear.

In young women exophthalmic goiter often follows in the wake of a disappointment in love; in women, too, it frequently follows the illnesses of children or parents during which they have had to endure the double strain of worry and of constant care. Since such strains usually fall most heavily upon women, they are the most frequent victims of this disease. Now, whatever the exciting cause of exophthalmic goiter, whether it be unusual business worry, disappointment in love, a tragedy, or the illness of a loved one, the symptoms are alike and closely resemble the phenomena of one of the great primitive emotions. How could disappointment in love play a role in the causation of Graves' disease? If the hypothesis which has been presented as an explanation of the genesis and the phenomena of fear be correct, then that hypothesis explains also the emotion of love. If fear be a phylogenetic physical defense or escape which does not result in muscular action, then love is a phylogenetic conjugation without physical action. The quickened pulse, the leaping heart, the accelerated respiration, the sighing, the glowing eye, the crimson cheek, and many other phenomena are merely phylogenetic recapitulations of ancestral acts. The thyroid gland is believed to participate in such physical activities. Hence it may well follow that the disappointed maiden who is intensely integrated for a youth will, at every thought of him, be subjected by phylogenetic association to a specific stimulation analogous to that which attended the ancestral consummation. Moreover, a happy marriage has many times been followed by a cure of the exophthalmic goiter which appeared in the wake of such an experience.

The victims of Graves' disease present a counterpart of emotional exhaustion. That the emotions in Graves' disease are abnormally acute is illustrated by my personal observation of the death of a subject of this disease from fear alone. Whatever the exciting cause of this disease, the symptoms are the same; just as in fear, the phenomena are the same whatever the exciting cause.

Figures 12 and 16 show the resemblance between the outward appearances of a patient with Graves' disease and of a person obsessed by fear. Fear and Graves' disease have the following phenomena in common: Increased heart-beat, increased respiration, rising temperature, muscular tremors, protruding eyes, loss in weight; Cannon has found an increased amount of adrenalin in the blood in fear and Frankel in Graves' disease; increased blood-pressure; muscular weakness; digestive disturbances; impaired nervous control; hypersusceptibility to stimuli; in protracted intense fear the brain-cells show marked physical changes, and in Graves' disease analogous changes are seen (Figs. 13 C and 15). In Graves' disease there seems to be a composite picture of an intense expression of the great primitive emotions. If Graves' disease be a disease of the great primitive emotions, or rather of the whole motor mechanism, how is the constant flow of stimulation of this complicated mechanism supplied? It would seem that there must be secreted in excessive amount some substance that activates the motor mechanism. The nervous system in Graves' disease is hypersusceptible to stimuli and to thyroid extract. It might follow that even a normal amount of thyroid secretion would lead to excessive stimulation of the hypersusceptible motor mechanism.

This condition of excessive motor activity and hyperexcitability may endure for years. What is the source of this pathologic excitation? The following facts may give a clue. In suitable cases of Graves' disease, if the thyroid secretion is sufficiently diminished by a removal of a part of the gland or by interrupting the nerve and the blood supply, the phenomena of the disease are diminished immediately, and in favorable cases the patient is restored to approximately the normal condition. The heart action slows, the respiratory rate falls, the restlessness diminishes, digestive disturbances disappear, tremors decrease, there is a rapid increase in the body weight, and the patient gradually resumes his normal state. On the other hand, if for a period of time extract of the thyroid gland is administered to a normal individual in excessive dosage, there will develop nervousness, palpitation of the heart, sweating, loss of weight, slight protrusion of the eyes, indigestion; in short, most of the phenomena of Graves' disease and of the strong emotions will be produced artificially (Figs. 15 and 23). When the administration of the thyroid extract is discontinued, these phenomena may disappear. On the other hand, when there is too little or no thyroid gland, the individual becomes dull, stupid, and emotionless, though he may be irritable; while if a sufficient amount of thyroid extract be given to such a patient he may be brought back to his normal condition.

Hence we see that the phenomena of the emotions may within certain limits be increased, diminished, or abolished by increasing, diminishing, or totally excluding the secretion of the thyroid gland.

Graves' disease may be increased by giving thyroid extract and by fear. It may be diminished by removing a part of the gland, or by interrupting the blood and nerve supply, or by complete rest. In addition, at some stage of Graves' disease there is an increase in the size and in the number of the secreting cells. These facts regarding the normal and the pathologic supply of thyroid secretion point to this gland as one of the sources of the energizing substance or substances, by means of which the motor phenomena of animals are executed and their emotions expressed.

Anger is similar to fear in origin and, like fear, is an integration and stimulation of the motor mechanism and its accessories. Animals which have no natural weapons for attack experience neither fear nor anger, while the animals which have weapons for attack express anger principally by energizing the muscles used in attack. Although, as has already been stated, the efficiency of the hands of man has largely supplanted the use of the teeth, he still shows his teeth in anger and so gives support to the theory that this emotion is of remote ancestral origin and proves the great persistence of phylogenetic association. On this conception we can understand why it is that a patient consumed by worry--which to me signifies interrupted stimulation, a state of alternation between hope and fear--suffers so many bodily impairments and diseases even. This hypothesis explains the slow dying of animals in captivity. It explains the grave digestive and metabolic disturbances which appear under any nerve strain, especially under the strain of fear, and the great benefits of confidence and hope; it explains the nervousness, loss of weight, indigestion--in short, the comprehensive physical changes that are wrought by fear and by sexual love and hate. On this hypothesis we can understand the physical influence of one individual over the body and personality of another; and of the infinite factors in environment that, through phylogenetic association, play a role in the functions of many of our organs. It is because under the uncompromising law of survival of the fittest we were evolved as motor beings that we do not possess any organs or faculties which have not served our progenitors in accomplishing their survival in the relentless struggle of organic forms with one another. We are now, as we were then, essentially motor beings, and the only way in which we can meet the dangers in our environment is by a motor response. Such a motor response implies the integration of our entire being for action, this integration involving the activity of certain glands, such as the adrenals (Cannon), the thyroid, the liver, etc., which throw into the blood-stream substances which help to form energy, but which, if no muscular action ensues, are harmful elements in the blood. While this motor preparation is going on, the entire digestive tract is inhibited. It thus becomes clear why an emotion is more harmful than action.

Any agency that can sufficiently inspire faith,--dispel worry,-- whether that agency be mystical, human, or divine, will at once stop the body-wide stimulations and inhibitions which cause lesions which are as truly physical as is a fracture. The striking benefits of good luck, success, and happiness; of a change of scene; of hunting and fishing; of optimistic and helpful friends, are at once explained by this hypothesis. One can also understand the difference between the broken body and spirits of an animal in captivity and its buoyant return to its normal condition when freed.

But time will not permit me to follow this tempting lead, which has been introduced for another purpose--the proposal of a remedy.

Worries either are or are not groundless. Of those that have a basis, many are exaggerated. It has occurred to me to utilize as an antidote an appeal to the same great law that originally excited the instinctive involuntary reaction known as fear-- the law of self-preservation.

I have found that if an intelligent patient who is suffering from fear can be made to see so plainly as to become firmly convinced that his brain, his various organs, indeed his whole being, could be physically damaged by fear, that this same instinct of self-preservation will, to the extent of his conviction, banish fear. It is hurling a threatened active militant danger, whose injurious influences are both certain and known, against an uncertain, perhaps a fancied, one. In other words, fear itself is an injury which when recognized is instinctively avoided. In a similar manner anger may be softened or banished by an appeal to the stronger self-preserving instinct aroused by the fear of physical damage, such as the physical injury of brain-cells. This playing of one primitive instinct against another is comparable to the effect produced upon two men who are quarreling when a more powerful enemy of both comes threateningly on the scene.

The acute fear of a surgical operation may be banished by the use of certain drugs that depress the associational power of the brain and so minimize the effect of the preparations that usually inspire fear. If, in addition, the entire field of operation is blocked by local anesthesia so that the associational centers are not awakened, the patient will pass through the operation unscathed.

The phylogenetic origin of fear is injury, hence injury and fear cause the same phenomena. In their quality and in their phenomena psychic shock and traumatic shock are the same. The perception of danger by the special senses in the sound of the opening gun of a battle, or in the sight of a venomous snake, is phylogenetically the same and causes the same effects upon the entire body as an operation under anesthesia or a physical combat in that each drives the motor mechanism. The use of local anesthetics in the operative field prevents nerve-currents from the seat of injury from reaching the brain and there integrating the entire body for a self-defensive struggle. The result, even though a part of the brain is asleep and the muscles paralyzed, is the same as that produced by the interception of the terrifying sound of the gun, or of the sight of the dangerous reptile, since the stimulation of the motor mechanism is prevented.

By both the positive and the negative evidence we are forced to believe that the emotions are primitive instinctive reactions which represent ancestral acts; and that they therefore utilize the complicated motor mechanism which has been developed by the forces of evolution as that best adapted to fit the individual for his struggle with his environment or for procreation.

The mechanism by which the motor acts are performed and the mechanism by which the emotions are expressed are one and the same. These acts in their infinite complexity are suggested by association-- phylogenetic association. When our progenitors came in contact with any exciting element in their environment, action ensued then and there. There was much action--little restraint or emotion. Civilized man is really in auto-captivity. He is subjected to innumerable stimulations, but custom and convention frequently prevent physical action. When these stimulations are sufficiently strong but no action ensues, the reaction constitutes an emotion. A phylogenetic fight is anger; a phylogenetic flight is fear; a phylogenetic copulation is sexual love, and so one finds in this conception an underlying principle which may be the key to an understanding of the emotions and of certain diseases.

PAIN, LAUGHTER, AND CRYING[*]

[*] Address delivered before the John Ashhurst, Jr.. Surgical Society of the University of Pennsylvania, May 3, 1912.

PAIN

Pain, like other phenomena, was probably evolved for a particular purpose-- surely for the good of the individual; like fear and worry, it frequently is injurious. What then may be its purpose?

We postulate that pain is one of the phenomena which result from a stimulation to motor action. When a barefoot boy steps on a sharp stone it is important that the injuring contact be released as quickly as possible; and therefore physical injury pain results and impels the required action. Anemia of the soft parts at the points of pressure results from prolonged sitting or lying in one position, and as a result pain compels a muscular action that shifts the damaging pressure--this is the pain of anemia; when the rays of the blazing sun shine directly upon the retina, pain immediately causes a protective muscular action--the lid is closed, the head turns away--this is light pain; when standing too close to a blazing fire the excessive heat causes a pain which results in the protective muscular action of moving away--this is heat pain; when the urinary bladder is acutely overdistended the resultant pain induces voluntary as well as involuntary muscular contraction-- this is evacuation pain; associated with defecation is a characteristic warning pain, and an active pain which induces the required muscular action--this, like the pain accompanying micturition, is an evacuation pain; in obstruction of the urinary passages and of the large and the small intestine the pain is exaggerated, as is the accompanying muscular contraction--this is a pathologic evacuation pain; when the fetus reaches full term and labor is to begin, it is heralded by pain which is associated with rhythmic contractions of the uterine muscle; later, many other muscles take part in the birth and pain is associated with all these muscular contractions--these are labor pains; when a foreign body, be it ever so small, falls upon the conjunctiva or cornea there results what is perhaps the acutest pain known, and quick and active muscular action follows--this is special contact pain. Special pain receptors are placed in certain parts of the nose, the pharynx, and the larynx, the stimulation of which causes special motor acts, such as sneezing, hawking, coughing. Curiously vague pains are associated with the protective motor act of vomiting and with the sexual motor acts--these may be termed nausea pains and pleasure pains. We now see, therefore, that against the injurious physical contacts of environment, against heat and cold, against damaging sunlight, against local anemia when resting or sleeping, the body is protected by virtue of the muscular action which results from pain. Then, too, for the emptying of the pregnant uterus, for the evacuation of the intestine and of the urinary bladder as normal acts, and for the overcoming of obstructions in these tracts, pain compels the required muscular actions, For passing gall-stones and urinary calculi, urgent motor stimuli are awakened by pain. For each of these diversified pains the consequent muscular action is specific in type, distribution, and intensity. This statement is so commonplace that we are apt to miss the significance and the wonder of it. It is probable that every nerve-ending in the skin and every type of stimulation represents a separate motor pattern, the adequate stimulation of which causes always the same response.

Let us pass on to the discussion of another and perhaps even more interesting type of pain, that associated with infection. Not all kinds of infection are painful; and in those infections that may be associated with pain there is pain only when certain regions of the body are involved. Among the infections that are not associated with pain are scarlet fever, typhoid fever, measles, malaria, whooping-cough, typhus fever, and syphilis in its early stages. The infections that are usually, though not always, associated with pain are the pyogenic infections. The pyogenic infections and the exanthemata constitute the great majority of infections and are the basis of the discussion which follows.

I will state one of my principal conclusions first, _i. e_., that the only types of infection that are associated with pain are those in which the infection may be spread by muscular action or those in which the fixation of parts by continued muscular rigidity is an advantage; and, further, as a striking corollary, that the type of infection that may cause muscular action when it attacks one region of the body may cause no such action when it attacks another region.

The primary, and perhaps the most striking, difference between the painless exanthemata and the painful pyogenic infections is that in the case of the exanthemata the protective response of the body is a chemical one,--the formation of antibodies in the blood, which usually produce permanent immunity,--while the response to the pyogenic infections is largely phagocytic. In the pyogenic infections, in order to protect the remainder of the body, which, of course, enjoys no immunity, every possible barrier against the spread of the infection is thrown about the local point of infection. How are these barriers formed? First, lymph is poured out, then the part is fixed by the continuous contraction of the neighboring muscles and by the inhibition of those muscles that, in the course of their ordinary function, would by their contractions spread the infection. Wherever there is protective muscular rigidity there is also pain. On the other hand, in pyogenic infections in the substance of the liver, in the substance of the kidney, within the brain, in the retroperitoneal space, in the lobes of the lung, in the chambers of the heart and in the blood-vessels of the chest and the abdomen, in all locations in which muscular contractions can in no way assist in localizing the disease, pyogenic infections produce no muscular rigidity and no pain. Apparently, therefore, only those infections are painful which are associated with a protective muscular contraction. This explains why tuberculosis of the hip is painful, while tuberculosis of the lung is painless.