As intimated, I do not know whether the impulse toward unity that inheres in the human mind is to be so easily driven from the field; whether we shall be satisfied in the long run to behold that light that irradiates the universe, broken a hundred-fold by the prisms of the single sciences. But one thing is certain. The more irresolute they are in whom the science of the future places its confidence, the more actively will they press forward who hold that the precious treasure of truth has long since been granted unto man, and who would fain forge with this heritage of the past the fetters of the future. After the Catholic church under Pius IX. had hurled in the face of modern culture and science its frantic _Anathema sit_, it began under his successor a much quieter, yet far more determined warfare. Like one of the famed lianas of the primeval tropical forests, it entwines the giant Science, to sap his best powers and slowly but surely to stifle his life. Whatever the modern mind with the help of freedom won by bitter struggles has gained in the knowledge of nature and of history, is twisted and turned, falsified and misinterpreted by hundreds and hundreds of busy hands until it has been fashioned to fit that ready-made scheme of things composed on the one hand of Catholic dogmatical teachings, and on the other of the Aristotelian-Thomistic philosophy. As many representatives as secular freethought can show, there will be found beside them to-day an ecclesiastical _advocatus diaboli_ who will neither rest nor cease until of the hero has been made a wretch and mangy heresiarch. Under protection of the principle of free inquiry, and with all the helps of science, a warfare of extermination is here carried on against all freedom of mind and all science, which is the more dangerous in proportion as the opponent loves to decorate himself with the borrowed plumes of science, and as he is able skilfully to mask his real designs. Catholicism is striving with untiring efforts to gain by the help of this reformed and modernised scholasticism, the mastery of the schools, of education, of the universities, and of the entire activity of science. And compared with the position of the representatives of modern thought it has decidedly the advantage. Not only is it in the possession of a unitary world-theory, but it defends that theory with most determined vigor and heedlessness against all differing views. The representatives of modern science, on the contrary, are not so fortunate as to possess inherited truth and infallible authority, and they not only have to contend with the formidable internal difficulties that stand in the way of a unitary formulation of their conception of the world, but frequently even avoid entering on this task with determination in order to make less prominent the contrast with the religio-theological system to which every exact scientific conception of the world must of necessity lead.