In the midst of this obvious falseness of prevalent pseudo-Christianity there is one favorable circumstance for the progress of a rational study of nature: its most powerful and bitterest enemy, the Roman Church, threw off its mask of ostensible concern for higher mental development about the middle of the nineteenth century, and declared a _guerre à l'outrance_ against independent science. This happened in three important challenges to reason, for the explicitness and resoluteness of which modern science and culture cannot but be grateful to the "Vicar of Christ." (1) In December, 1854, the pope promulgated the dogma of the immaculate conception of Mary. (2) Ten years afterwards--in December, 1864--the pope published, in his famous _encyclica_, an absolute condemnation of the whole of modern civilization and culture; in the _syllabus_ that accompanied it he enumerated and anathematized all the rational theses and philosophical principles which are regarded by modern science as lucid truths. (3) Finally, six years afterwards--on July 13, 1870--the militant head of the Church crowned his folly by claiming _infallibility_ for himself and all his predecessors in the papal chair. This triumph of the Roman _curia_ was communicated to the astonished world five days afterwards, on the very day on which France declared war with Prussia. Two months later the temporal power of the pope was taken from him in consequence of the war. These three stupendous acts of the papacy were such obvious assaults on the reason of the nineteenth century that they gave rise, from the very beginning, to a most heated discussion even within orthodox Catholic circles. When the Vatican Council proceeded to define the dogma of infallibility on July 13, 1870, only three-fourths of the bishops declared in its favor, 451 out of 601 assenting; many other bishops, who wished to keep clear of the perilous definition, were absent from the council. But the shrewd pontiff had calculated better than the timid "discreet Catholics": even this extraordinary dogma was blindly accepted by the credulous and uneducated masses of the faithful.