THE WISH "to know the cause of things" is as old as man- kind itself. In medicine the scientific period dawned at the moment when the question as to the connexion of disease with environment was clearly propounded by Diodorus and by Hippo- crates, "the father of medicine." In former times men were generally satisfied, and they are fre- quently satisfied to-day, with the vaguest conceptions of things, conceptions based on the common ground of a search after animate causes or (...) personifications. Universal knowledge is plainly unat- tainable in a given section of time ; hence men have always been forced to piece out in imagination part of the lacking facts,—that is to theorise; and the form such speculation takes on is naturally in accordance with the measure of cultivation prevailing at the time. Even now, as is clearly shown by a glance at the concep- tions of image-worship among educated and uneducated individuals and peoples, there is for wide strata of society an imperative neces- sity for personification, for animate cause... (shrink)