按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
g of forceful uplifting environmental stimuli？
There are now； as there were in Darwin's day； many who feel that man is degraded from his high estate by the conception that he is not a reasoning； willing being； the result of a special creation。 But one may wonder indeed what conception of the origin of man can be more wonderful or more inspiring than the belief that he has been slowly evolved through the ages； and that all creatures have had a part in his development； that each form of life has contributed and is contributing still to his present welfare and to his future advancement。
Recapitulation
Psychology；the science of the human soul and its relations； under the mechanistic theory of life； must receive a new definition。 It becomes a science of man's activities as determined by the environmental stimuli of his phylogeny and of his ontogeny。
On this basis we postulate that throughout the history of the race nothing has been lost； but that every experience of the race and of the individual has been retained for the guidance of the individual and of the race； that for the accomplishment of this end there has been evolved through the ages a nerve mechanism of such infinite delicacy and precision that in some unknown manner it can register permanently within itself every impression received in the phylogenetic and ontogenetic experience of the individual； that each of these nerve mechanisms or brain patterns has its own connection with the external world； and that each is attuned to receive impressions of but one kind； as in the apparatus of wireless telegraphy each instrument can receive and interpret waves of a certain rate of intensity only； that thought； will； ego； personality； perception； imagination； reason； emotion； choice； memory； are to be interpreted in terms of these brain patterns； that these so…called phenomena of human life depend upon the stimuli which can secure the final common path； this in turn having been determined by the frequency and the strength of the environmental stimuli of the past and of the present。
Finally； as for life's origin and life's ultimate end； we are content to say that they are unknown； perhaps unknowable。 We know only that living matter； like lifeless matter； has its own place in the cosmic processes； that the gigantic forces which operated to produce a world upon which life could exist； as a logical sequence； when the time was ripe； evolved life； and finally that these cosmic forces are still active； though none can tell what worlds and what races may be the result of their coming activities。
A MECHANISTIC THEORY OF DISEASE＇*＇
＇*＇ Oration in Surgery。 Delivered at the 147th Annual Meeting of the Medical Society of New Jersey； at Spring Lake； N。 J。； June 11； 1913。
In this address the paragraphs which were taken from the preceding paper； 〃A Mechanistic View of Psychology；〃 have been omitted； those portions only being republished in which the premises have been applied in a discussion of certain medical problems rather than of psychological problems。
The human body is an elaborate mechanism equipped first for such conflict with environment as will tend to the preservation of the individual； and second for the propagation of the species； both of these functions； when most efficiently carried out； tending to the upbuilding and perfection of the race。 From the date of Harvey's discovery of the circulation of the blood； to the present day； the human body has been constantly compared to a machine； but the time for analogy and comparison is past。 I postulate that the body is itself a mechanism responding in every part to the adequate stimuli given it from without by the environment of the present and from within by the environment of the past； the memory of which is stored in the central battery of the mechanism the brain。 * * * * * * * * * * * * * * * * * * * *
If the full history of the species and of the individual could be known in every detail； then every detail of that individual's conduct in health and disease could be predicted。 Reaction to environment is the basis of conduct； of moral standards； of manners and conventions； of work and play； of love and hate； of protection and murder； of governing and being governed； in fact； of all the reactions between human beingsof the entire web of life。 As Sherrington has stated； 〃Environment drives the brain； the brain drives the various organs of the body；〃 and here we believe we find the key to a mechanistic interpretation of all body processes。
On this basis we may see that the activities of life depend upon the ability of the parts of the body mechanism to respond adequately to adequate stimulation。 This postulate applies not only to stimuli from visible forces； but to those received by the invasion of the micro…bodies which cause pyogenic or non…pyogenic infections。 In the case of dangerous assaults by visible or invisible enemies； the brain； through the nerves and all parts of the motor mechanism； meets the attack by attempts at adaptation。 Recovery； invalidism； and death depend upon the degree of success with which the attacking or invading enemies are met。 Questions regarding disease become； therefore； questions in adaptation； and it is possible that； when studied in the light of this conception； the key to many hitherto unsolved physical problems may be found。
Perhaps no more convincing proof of our thesis may be secured than by a study of that ever…present phenomenonpain。 In whatever part of the body and by whatever apparent cause pain is produced； we find that it is invariably a stimulation to motor activity whose ultimate object is protection。 Thus by the muscular action resulting from pain we are protected against heat and cold； against too powerful light； against local anemia caused by prolonged pressure upon any portion of the body。 So； too； pain of greater or less intensity compels the required emptying of the pregnant uterus and the evacuation of the intestine and the urinary bladder。
It should be noted that in every instance the muscular activity resulting from pain is specific in its type； its distribution； and its intensity； this specificity being true not only of pain which is the result of external stimulation； but also of the pain associated with certain types of infection。
Pain； however； is not the only symptom of the invasion of the body by pyogenic or parasitic organisms。 Fever； invariably； and chills； often； accompany the course of the infections。 Can these phenomena also be explained as adaptations of the motor mechanism for the good of the individual？
As the phenomena of chills and fever are most strikingly exhibited in malaria； let us study the course of events in that disease。 It is known that the malarial parasite develops in the red blood…corpuscles； and that the chills and fever appear when the cycle of parasitic development is complete and the adults are ready to escape from the corpuscles of the blood plasma。 Bass； of New Orleans； has proved that the favorable temperature for the growth of the malarial organism is 98'0； and that at 102'0 the adult organisms will be killed； though the latter temperature is not fatal to the spores。 The adult life of the malarial parasite begins after its escape into the blood plasma； and it is there that the organism is most susceptible to high temperature。 We must infer； therefore； that the fever is an adaptation on the part of the host for despatching the enemy。
What； then； may be the protective part played by the chill？ A chill is made up of intermittent contractions of all the external muscles of the body。 This activity results in an increase of the body heat and in an anemia of the superficial parts of the body； so that less heat can be lost by radiation。 By this means； therefore； the external portions of the body contribute measurably to the production of the beneficent and saving fever。
It must be remembered that this power of adaptation is not peculiar to man alone； but that it is a quality shared by all living creatures。 While the human body has been adapting itself for self…protection by producing a febrile reaction whereby to kill the invading organis