Pierre Charles Alexandre Louis

“Researches on the effects of bloodletting in some inflammatory diseases, and on the influence of tartarized antimony and vesication in pneumonitis (1836) Tr. C. G. Putnam @archive.org”

“Recherches sur les effets de la saignée dans quelques maladies inflammatoires, et sur l'action de l'émétique et des vésicatoires dans la pneumonie (French)”

“Pierre-Charles-Alexandre Louis and the evaluation of bloodletting @The James Lind Library”

“creator:"Louis, P. C. A. (Pierre Charles Alexandre), 1787-1872" @archive.org”

“My sole expectation is to lead some, who might otherwise be ignorant of them, among my brethren of the present day, to study works which I esteem as among the most valuable certainly, if not the most valuable, which any age has furnished us in regard to medicine. ...these principles may be added to, they may be enlarged, limited and modified, and yet the system may be maintained; and it will still derive its support from the first labors devoted to its erection as much as from the last.”

“By the middle of the 1830s the numerical method, which Louis enshrined as the doctrinal heart of his new Société médicale d'observation, had become probably the most fiercely contested proposition in all of French medicine.”

“Pierre Charles Alexandre Louis should be honored as a primary author of the "numerical method." By "numerical method" he meant that the stages of disease and therapeutic outcomes should be expressed in terms of numbers and not merely as a set of verbal descriptions. ...This method seems so sensible that it is difficult to see why it was resisted by the medical establishment.”

“The objection made to the numerical method, to wit, the difficulty or impossibility of forming classes of similar facts, is alike applicable to all the methods that might be substituted; that it is impossible to appreciate each case with mathematical exactness, and it is precisely on this account that enumeration becomes necessary; by so doing, the errors, (which are inevitable,) being the same in two groups of patients subjected to different treatment, mutually compensate each other, and they may be disregarded without sensibly affecting the exactness of the results.”

“In any epidemic... let us suppose five hundred of the sick, taken indiscriminately, to be subjected to one kind of treatment, and five hundred others, taken in the same manner, to be treated in a different mode; if the mortality is greater among the first, than among the second, must we not conclude that the treatment was less appropriate, or less efficacious in the first class, than in the second ? It is unavoidable; for among so large a collection, similarities of condition will necessarily be met with, and all things being equal, except the treatment, the conclusion will be rigorous.”

“All [knowledge] comes from experience, it is true, but experience is nothing if it does not form collections of similar facts. Now, to make collections is to count.”

“Between the one who counts the facts, grouped according to their resemblance, in order to know what to believe regarding the value of therapeutic agents and him who does not count but always says "more or less frequent," there is the difference between truth and error, between something that is clear and truly scientific and something that is vague and without value—for what place is there in Science for that which is vague?”

“Without the aid of statistics nothing like real medicine is possible.”