However, this reproach is mitigated if we consider that medicine did not accord a home to superstition of its own free will, or even from a predilection for the heresies of other disciples, but it did so under compulsion; for the religious, the philosophical, the physical views which forced the entrance of superstition into medical science were almost always the views of a formidable party. It is a fact sufficiently demonstrated by history that powerful and far-reaching predilections of the popular mind resistlessly hurry along whatever is in their path. Such mental currents are the products of their period; they are the immediate result of the general sentiment and feeling of their time, and for this very reason they successfully overcome resistance. The opinion of a single individual may raise a protest against the spirit of the age, but this resistance is always bound to be in vain. The opinion of a single individual, even if it actually represents the truth, is absolutely powerless to resist the spirit of the age which, with elemental force, compels obedience. Therefore, the courageous, truth-seeking resistance which was offered to the heresies of _Medicina Astrologica_ by Pico of Mirandola and Girolamo Fracastori was bound to be futile, because astrology was a genuine child of its time, and therefore held irresistible sway over thought and sentiment. If religion and philosophy so often interfered with the development of medicine, this was only possible because the general tendency of the contemporary mind was thoroughly absorbed in this or that religious or philosophical idea. For each domain of human activity must needs be a mere reflection of the tendency which guides the mind of its period. This is a law which, with iron force, dominates the development of culture. Superstition in medicine, therefore, was bound to flourish and thrive whenever it harmonized with the spirit of the age. This law, tho it may have checked the development of our science, nevertheless holds out the certain promise of a period, the intellectual power of which will thoroughly clear away all relics of superstition, which, still persisting in the minds of the many, drives them to the faith-curist and to the quack. VII MEDICAL SUPERSTITION AND INSANITY