And how often the hypotheses of profane sciences change! “Laymen are astonished,” says _H. Poincaré_, “that so many scientific theories are perishable. They see them thrive for a few years, to be abandoned one after the other; they see wrecks heaped upon wrecks; they foresee that theories now fashionable will after a short while be forgotten, and they conclude that these theories are absolute fallacy. They call it the bankruptcy of science” (Wissenschaft u. Hypothese, German by _F. Lindemann_, 2d ed., 1906, 161). The conclusion is certainly unjustified, but the fact itself remains. Is it then a loss to science when faith opposes in the field of religion these variations of opinion with fixed dogmas? Or are these perhaps of less worth, or less certain than their contraries? Is the dogma of the existence of God of less value than atheism? Is the conviction of the existence of a world of spirits less substantial than the philosophy of materialistic monism? Is the doctrine of the origin of the human soul from the creating hand of God found inferior to the notion that the soul has developed from the lower stages of animal life? Should the holy teaching of Christianity, doctrines believed by the best periods in the world’s history, believed in and professed by minds like those of an _Augustine_, a _Thomas_, and a _Leibnitz_; doctrines that since their appearance on earth have always attracted the noble and good, and repelled chiefly the base and immoral; doctrines that still wait for their first unobjectionable refutation—should such doctrines be less sure than the innumerable, ever-changing suggestions of unregulated thought, apparently directed by an aversion to everything supernatural? Erravimus. Yet another fact may be pointed out. It is an undeniable fact that science, after straying for some time, is not unfrequently _compelled to return to what is taught by faith and the Church_, thus confirming the truth of the faith. Frequently the new theory has come on like a tornado, sweeping all minds before it. But the tempest was soon spent, the minds recovered their balance and the hasty misjudgment was recognized.