PREFACE TO THE SEVENTH EDITION. vii 



from other incomplete sciences, and that it must be conducted 

 by itself as an independent and peculiar branch of knowl- 

 edge; after showing, farther, that the empirical method of 

 investigation is the only rational and proper one for the 

 study either of therapeutics, or of any other department of 

 natural science, I pointed out more precisely what material 

 we already possessed for the establishment of therapeusis as 

 an independent empirical study; showed what still remained 

 to be done, and how that which is still lacking is to be obtained. 

 I then demonstrated that, before all else, empirical knowledge 

 requires a profound and thorough acquaintance with facts, and 

 that the more accurate the observation, so much the more cor- 

 rect and trustworthy must the deduction be, and that observa- 

 tions in therapeusis, if inaccurate or imperfect, are prolific of 

 false conclusions and of erroneous proceedings, just as in other 

 branches of natural science. I explained that, when ancient 

 therapeutic laws, based sometimes upon the experience of cen- 

 turies, have proved false, the error has been due to inexact and 

 incomplete observation; that the general impression that a 

 remedy has done good or harm, in this or that disease, is utterly 

 worthless in a scientific point of view. I declared that empiri- 

 cal matter, capable of affording trustworthy and useful rules for 

 the treatment of disease, is only to be obtained by the most 

 careful and intelligent investigation of the healing effects of 

 medicaments ; that no sure basis for therapeusis can be estab- 

 lished until this shall occur ; until clinical teachers and physicians, 

 particularly those at the head of the science, familiar with all 

 the accessories to diagnosis, shall comprehend that their main 

 task is, most carefully (and, where possible, objectively) to ana- 

 lyze the symptoms of a disease, prior to and subsequent to the 

 administration of a supposed remedy ; that such (no doubt very 

 laborious) investigations have hitherto been totally neglected, 

 because no one expected to obtain any results from such a method 

 of study ; but that these pessimist views evince an undervalua- 

 tion of the brilliant progress of physical diagnosis, of physiol 



