BEFORE the last chapter of this treatise was in print, its lamented author had passed out of this world, in which he had done invaluable service to the Church of GOD.

While the present translation was passing through the press, the translator also, EDWARD HENEAGE DERING, was suddenly called to his reward. The last composition that he printed (in the Tablet, Nov. 19, 1892), was the following short memoir of his friend and master in Scholastic science, FATHER MATTEO LIBERATORE:

"In Memoriam.

"Sixty-seven years ago a boy of fifteen, whose book-learning had till then been in abeyance, by reason of his having wonderfully been the mainstay of his widowed mother's house from the age of ten, entered a Jesuit school in Naples, and, rapidly passing all his competitors, was in the following year a novice in the Society of JESUS. He was Professor of Philosophy from 1837 -- only twelve years after going to school -- till the Revolution of 1848 forced him into exile, from which he returned at the imminent risk of his life, and was made Professor of Theology at Naples. The risk was evident, because his name was on the list of the proscribed, as intended for the patriot's dagger. In 1850 he co-operated in founding the Civiltà Cattolica, to defend the Church, the Holy See, and notably the teaching of ST. THOMAS. Without him that invaluable periodical would have died still-born, instead of doing the great work that it has done and continues to do. But this necessitates a brief retrospect. When he began teaching philosophy as a professor, thirteen years before, he found it infected with dangerous errors. We cannot speak of them here for want of space, but certain it is that the Angelic Doctor was generally forgotten, discredited, misrepresented, and that false philosophy was taught even within the Church. He was the first in the field against that, published his Institutiones Philosophicae in 1840, and continued to fight the good fight as long as Almighty God willed that his life should last. That man was FATHER MATTEO LIBERATORE, who died in Rome on the 18th of last October, eight months after the death of his great co-operator and confrère, FATHER GIOVANNI MARIA CORNOLDI. When two such men are taken away from the Church militant, one can only turn to Almighty God and say, Fiat voluntas Tua. To myself the loss of FATHER LIBERATORE is a personal grief and an irreparable loss. Dominus dedit . . . Dominus abstulit. . . sit nomen Domini benedictum. -- Baddesley Clinton, Nov. 19, 1892."

Mr. Dering's life and literary labours had been devoted to the enlightenment and conversion of his countrymen. He died, as he had desired to do, in harness; and, lamenting the greatness of his loss, the many who loved him, can only echo his last printed words: Dominus dedit. . . Dominus abstulit. . . . sit nomen Domini benedictum.

PREFACE.

WHY THIS TREATISE WAS WRITTEN.

HAVING for many years openly defended the Philosophy of St. Thomas, even in what concerns the fundamental doctrines of organic and inorganic nature, we think it time to treat that subject, not merely touching on one or another point, but dealing with those doctrines philosophically.

In Italy, where Masonic influence is now felt in every department of Government, nothing has been omitted by which the minds and hearts of our young men could be turned away, not only from the religious teaching of the Catholic Church, but also from all philosophical doctrines that are not against Religion. The teaching of Metaphysics was made over years ago to professors who only corrupted their pupils by the German transcendentalism of Kant, Hegel, Schelling and others but, inasmuch as that philosophy was abstruse, ill-suited to the wicked purpose intended and very apt to produce weariness, Metaphysics, properly so-called, were afterwards proscribed in the schools, to make way for Positivism and Materialism.

If in our Catholic schools Physical Sciences were rightly and fully taught, the evil would be less. But what we call Government schools are, for the most part, obligatory; and, by reason of the method prescribed, even for private schools it is impossible to elucidate those doctrines without which the pupils are neither instructed sufficiently nor prepared for resisting the temptations of the Universities.

By this treatise we cannot hope to be of use directly and immediately in the public schools of the Government: but we can hope to do something indirectly and mediately.

In the second place, many who have a great reverence for the wisdom of the Angelic Doctor, and, in obedience to the Vicar of Jesus Christ, declare their adhesion to his doctrines, know too little of the fundamental questions that belong to Physics. Many have confused ideas about them, and therefore are liable to be taken in by the sophisms and the authority of men who pass as wise and learned in such things. Hence they either give in or vacillate, accepting as probable what is not only improbable, but also absurd and bad.

These and other reasons have induced us to put before our readers, especially those who are given to the study of philosophy and natural sciences, that system which we call the Physical System, whose principles were certainly professed by the Angelic Doctor, St. Thomas. It is, or should be, unnecessary to say that we are not going to rake up exploded doctrines of the old physicists. The habit of confusing such opinions with the philosophical principles of rational Physics, ascribing to the latter what belongs to pure experiment, has led many to attack truth with the hatred due to error and to put the wisest in the category of quacks.