phlogiston theory was no longer adequate to explain all known facts were the facts it attempted to explain re-interpreted by the genius of Lavoisier in terms of the modern theory of oxidation and reduction.
In considering the value and influence of all these now abandoned theories, we should keep in mind that the value of a theory in science at a particular epoch depends not so much upon its absolute truth or reality as upon the extent that it assists in classifying and accounting for observed facts and in stimulating to new observations or experiments.
It will be seen how the above theories are linked together and how each served for its own century and prepared the way for its successor. Nevertheless, the greatest service which Paracelsus contributed, to the development of chemistry was in the influence which his teaching and his example and his widely published works exerted in battering down the wall of infallible dogma that for centuries had protected the doctrines of medicine from any important development from the side of its relation to chemistry. His unceasing criticism of the defects of the theory and practise of the ancient authorities, his trenchant arguments for a broader experimental basis for the science, his severe arraignments of the ignorance and venality of the physicians of his time; his ridicule and defiance of their sacred authorities, together with the constant reiterations of the knowledge of chemistry as essential to understanding the life processes in health and disease, exerted a powerful influence not indeed so much upon the university faculties or the physicians schooled in their doctrines as upon the younger and more progressive generation of students. Also his appeal to the chemists as such to find in the future of medicine a field of endeavor more promising of success than the as yet unrewarded efforts for the transmutation of the base metals into gold, found much following among those who were interested in the study of chemistry. If we recall that most of the scholarly trained chemists were also physicians, we can understand how this combination of medical and chemical aims advocated by Paracelsus found fertile soil among young physicians and medical students as among chemists of less conventional training.
That this is true is shown, not only by the tremendous vogue of his printed works, but also by the fierce contest which for a century split the medical profession of Europe into hostile and embittered factions of Paracelsists and anti-Paracelsists—adherents of the new chemical medicines and advocates of the older Galenic remedies.
While the greatest service of Paracelsus was to shatter confidence in dogmas revered for the sake of their authors' great names, the new doctrines which he set up to replace the dogmas he combated were, in many respects, as fantastic and unscientific as the earlier ones. Nevertheless, the shattering of the blind faith in traditional teachings, which gave to Paracelsus his popularity and following, necessarily operated also to prevent his new doctrines from becoming considered as sacred
