The history of medicine is closely interlinked with the development of theology. The errors of one are for the most part reflected in the mistakes of the other. No matter how obscure and dark the origin of either, whether derived from ignorance and superstition or not, the ultimate achievement alone must be taken into consideration. We do not reject chemistry because it originated in alchemy, we do not disregard astronomy because its roots are entwined with the teachings of astrology, and so in theology and medicine we look to the final issue. The statements set forth in this book should not be construed as reflecting the development of theology or medicine at the time, but as the belief of the people existing in these periods. Philosophy may have been pure, but if the mind of man was faulty the responsibility must not be laid at the door of science. It is the function of the historian truthfully to depict the thought and spirit of the time of which he writes. This has been attempted in the present work. It is not a criticism of a system, but a criticism of man. There can be no doubt that absurd superstitions are still existent for which the twentieth century will be severely criticized in time to come. Thus the words of our martyred President may well be used as a motto for this book: "With malice towards none, with charity for all." The last chapter of this book has been added by the translator, as it seemed necessary for the full discussion of the subject.

Faith and superstition are twin brothers. Altho the former leads humanity to its sublimest ideals and the latter only presents us with a caricature of human knowledge, both are children of the same family. Both originate in a sense of the inadequacy of human science in regard to natural phenomena. The fact that the most important processes of organic life can not be traced to their ultimate origin, but that their investigation will soon lead to a point of irresistible opposition to further analysis, has always called forth a feeling of impotency and dependence in the human mind. This consciousness of being dependent upon factors which are entirely beyond human understanding has thus given rise to the metaphysical need of reflecting upon these mysterious factors, and bringing them within reach of human comprehension. Humanity, in attempting to satisfy such a metaphysical requirement from an ethical standpoint, created faith, which subsequently found expression in the various forms of religion. It is not within the scope of this essay to consider how far Divine revelations have been vouchsafed on this subject.