We have heretofore said that the physicians of primitive times reasoned very little on morbid phenomena, or the effects of remedies ; that they contented themselves to observe which were the remedies that would heal certain diseases, and to employ thereafter the same means in like cases.
It appears that during the mystical period no other plan was followed. Hippocrates, Celsus, Galen, and all the historiographers of Medicine, agree in saying that before the introduction of philosophy into this science, i. e., before the age of Pythagoras, there was no other rule than empiricism. But by this, these authors do not allude to rational empiricism, which had its origin much later, in the school at Alexandria : they speak of instinctive or natural empiricism, which we have referred to in the primitive period, and which is still daily followed by persons, strangers to the art, when they obtrude themselves to give counsels to the sick. These persons have constantly in their mouths these words : " I have seen a disease similar to this cured by such a remedy." Their reasoning, however gross it appears to us, is based on an incontestable principle, that may be stated as follows : Remedies which have cured a disease, must he equally efficacious in curing analogous cases.
Nothing is clearer, nothing is truer, than this aphorism : it has all the infallibility of a mathematical axiom ; and as the medical practice of ancient times rested on this, an author that we have already quoted says with truth: " Medicine for a long time has been in possession of all that is really necessary in regard to principles and method. With these guides, numerous and valuable discoveries have been made luring a long course of centuries ; and the rest will be discovered, if capable men, instructed in the discoveries of the ancients, shall take these for the point of departure in their researches. But they who reject and disdain the past, and attempt other methods and other ways, pretending to have found something new, will be mistaken and will mislead others."( Oeuvres d'Hippocrate. " Traite de l'Ancienne Medecine," § II Translation of M. Littre. Paris, 1839)
Nevertheless, complaints are ceaseless of the uncertainty and instability of medicine. The science is accused of having no stable principles to shelter it from the caprices of fashion and in the changes of systems. The masters of the art themselves furnish often the examples for this exaggerated declamation.
Pinel, frightened by the difficulties of medical practice, blames justly the presumption of a writer of the last century (Picairn), who promised nothing less than the solution of this general problem " A disease being given, to find the remedy." But does he not himself fall into a contrary excess, and does he not mistake the true destination of Medicine, when he proposes for the end of his labors nothing but the resolution of the following question : " Determine the true character of a given disease, and its position in the nosological scale.(Nosograpkie Philos.," introcl., page iv) Does not this take from the medical arch its most essential support, its keystone - therapeutics ?
Bichat expresses himself in these terms, on the same subject: " Materia medica, an assemblage of incoherent opinions, is perhaps, of all the physiological sciences, that which most exhibits the contradictions of the human mind. In fact, it is not a science for a methodic spirit ; it is a shapeless assemblage of inexact ideas, of observations often puerile, of imaginary remedies strangely conceived and fastidiously arranged. It is said that the practice of Medicine is repulsive. I will go further : no reasonable man can follow it, if he studies its principles as set forth in our materia medicas." (Bichat, " Anat. Geuerale." Consid. Generates, § II)
Broussais is not less explicit nor less vehement in his condemnation of the therapeutics of his predecessors. (See, among others, the xv. chapter of l'Examen des Doctrines Medicale, entitled, " De la Certitude en Medecine."
Complaints so unanimous have a cause that it is the duty of the historian to explain. Those who make them are not ignorant, certainly, of the axiom set forth above, and which is in accordance with common sense. Thus it is not, as think the vulgar, the absence of a fundamental principle in practical Medicine which pains them, but rather the difficulties, always great and sometimes insurmountable, that are met with in its application.
To obtain a conception of these difficulties, it will suffice to glance at one of the most simple cases in the practice. Suppose, for example, that a case of palpitation of the heart is to be treated. On this simple announcement a medicaster or an apothecary would not hesitate to prescribe digitalis, or thridace, or some other remedy indicated in the formulary, to combat this symptom.
The true physician, one who adds to the lights of science a sense of duty, would not be so prompt : he would, in the first place, know all the associated circumstances ; then he would proceed to examine the patient by commencing at the organ where the functional trouble was the most apparent : in short, it would be only after having carefully explored all the viscera and all the functions of the body, that he would feel authorized to prescribe the treatment ; for he is aware, that often the mute suffering of an organ distant from the heart may be the cause of the palpitations, so that of ten individuals who complain of palpitation, perhaps in not more than two would the same remedies be applicable. Moreover, all is not finished when a practitioner has properly established his diagnosis. It is yet necessary for him to choose the remedies proper to fulfill the curative indications ; that is, he must be well posted in all the internal and external resources of therapeutics. Finally, it is necessary that he secure, on the part of the patient and the attendant, the faithful execution of his directions, and that he carefully observe their effects.
If the enlightened and conscientious practice of Medicine offers so much difficulty in the simpler cases, what must it be when it is necessary to treat complicated and insidious affections, such as constitutional syphilis, or tetters, or scrofula, or leprosy, etc., which, concealed in the economy for months and years, deepening their roots, and changing the fluids, reveal themselves only in an ambiguous manner, after having invaded the entire system, whence it is almost impossible to dislodge them ?
But these cases, embarrassing as they are, afford the practitioner, at least, the opportunity of studying and reflecting upon them, aiding himself by the opinions of authors, and trying various means of cure. It is not so, though, when he finds himself in the presence of the plague, the cholera, pernicious fevers, and other epidemics, which fall like a tornado upon the people, carrying off, without distinction, the young, the old, the feeble, and the robust, overturning at once all the functions of the organism, assuming the most varied forms, and striking so rapidly that they allow the physician neither time to collect his thoughts or to make experiments.
Under these calamitous circumstances, he has need, not only of science and discernment, but also of sang-froid, devotion, and courage to contest some victims, at least, with the devastating scourge. And at last, when, notwithstanding so many causes of error, he arrives at the establishment of an efficacious mode of treatment, it often occurs that the constitution of the epidemic is so modified that he is obliged to commence his researches anew.
In other sciences, as physics and chemistry, there is an opportunity of reiterating the same experiment as often as necessary. The agents which concur to produce these, are at our disposal, and we can so isolate them as to obtain only their pure effects, and free from all foreign influences. In practical Medicine it is entirely different ; here, nature and accidents. i. e. diseases, furnish us the opportunities of experimenting ; but, in the first place, the elements of these experiments are never identical ; secondly, much time may elapse before an occasion presents itself for renewing them ; and, thirdly, it is impossible to isolate the patients from a multitude of influences that alter the therapeutical results. Hence it follows, that it is impossible rigorously to infer one medical fact from another.
These views show why along series of observations, collected by a great number of observers, at different epochs and in different climates, are necessary to arrive at the discovery of a curative method - to the acquisition of a therapeutical principle. It is this which has, in all time, discouraged great practitioners, and has driven one of the most illustrious of them to write this sentence, in which he betrays a profound melancholy : " Art is long, life is short, opportunity fleeting, experience deceptive, and judgment difficult. It is necessary, not only that the physician do all he can, but also the patient himself, as well as his attendants and friends, co-operate with him." - Hippoc. App. liv. 1.
Notwithstanding so many obstacles, which have been supposed insurmountable, man has come, by force of research, perseverance, and genius, to find some remedies of marvelous efficacy in certain cases, and to trace some rules which approximate therapeutics to the exact sciences, as we shall hereafter show.
From History of Medicine by P.V. Renouard M.D.