228 NEUROLOGY 



We need, in short, to supplement our researches into the direct 

 and local effects of a given lesion by a study into the more or less 

 widespread modifications of energy which the organism exhibits 

 as a result of the lesion, and which it is customary to designate as 

 indicative of an attempt 1 to repair the damages which the lesion 

 has induced. We need also to learn a great deal more about the 

 genesis of symptoms, even though we must remain ignorant about 

 the genesis of what one would call disease, in an anatomic sense. 



The signs of readjustment constitute, in fact, all that we can 

 really learn in the study of disease, for the disease-process, con- 

 sidered independently of them, is an abstraction, without real ex- 

 istence. 



And if this is so, then all the indications of this process of read- 

 justment are proper objects of our study, whether they be of the 

 nature of symptoms or of anatomic marks, whether they concern 

 special localities and organs which are the seat of primary "les- 

 ions," or other parts standing in functional relationship to them, 

 and even though they point to changes which are not to be classed 

 as morbid, but rather as modifications favorable to health. The 

 reactions after a so-called "healthy" fatigue, which often lead to 

 new and better powers of endurance, would be of this latter sort, 

 and the same is true of those reactions through which immunity 

 is secured after infectious disease. At such points as these, "dis- 

 ease" and "health" touch hands, and it becomes, indeed, evident 

 that neither disease nor health is a definite condition, but that both 

 of them are movements toward some relatively endurable equi- 

 librium, 2 a goal which is never fully reached. 



Of course, to a certain extent, investigations of this sort are daily 

 made by every student, but the question is: In what direction is 

 it now most important that the emphasis of research should be 

 thrown and scientific instincts developed? Imitation and fashion 

 play a large part, even in scientific investigation, and the almost 

 universal tendency to bend all energies to the search for the phys- 

 ical evidence of localized lesions has led too often to a disregard 

 of disturbances usually classified as functional. Not only is it es- 

 sential that "clinical medicine" should be studied in the light of 

 "physiology," but the field of morbid psychology, which now lies 

 untilled save by a few students, is one of the utmost practical 

 importance for each practitioner. 



Welch, cited below) are able, under special stimulation, to work with more than 

 usual effectiveness. This extra force is called " physiologic reserve." 



1 The word "attempt" and others of like meaning are here used not in a tele- 

 ologic, but only in a descriptive sense, for it seems plain that we must follow 

 the example of the biologists who have studied the problems of growth and of 

 repair (compare Thomas Hunt Morgan, " Regeneration ") and admit that there 

 is no justification for assuming a special vis medicatrix naturae. 



* " Stationary Equilibrium. (Ostwald, Die Philosophic der Natur.) 



