In the domain of Ontology there are many scholastic theories and discussions which are commonly regarded by non-scholastic writers as possessing nowadays for the student of philosophy an interest that is merely historical. This mistaken notion is probably due to the fact that few if any serious attempts have yet been made to transpose these questions from their medieval setting into the language and context of contemporary philosophy. Perhaps not a single one of these problems is really and in substance alien to present-day speculations. The author has endeavoured, by his treatment of such characteristically “medieval” discussions as those on Potentia and Actus, Essence and Existence, Individuation, the Theory of Distinctions, Substance and Accident, Nature and Person, Logical and Real Relations, Efficient and Final Causes, to show that the issues involved are in every instance as fully and keenly debated—in an altered setting and a new terminology—by recent and living philosophers of every [pg viii] school of thought as they were by St. Thomas and his contemporaries in the golden age of medieval scholasticism. And, as the purposes of a text-book demanded, attention has been devoted to stating the problems clearly, to showing the significance and bearings of discussions and solutions, rather than to detailed analyses of arguments. At the same time it is hoped that the treatment is sufficiently full to be helpful even to advanced students and to all who are interested in the “Metaphysics of the Schools”. For the convenience of the reader the more advanced portions are printed in smaller type.
The teaching of St. Thomas and the other great Schoolmen of the Middle Ages forms the groundwork of the book. This corpus of doctrine is scarcely yet accessible outside its Latin sources. As typical of the fuller scholastic text-books the excellent treatise of the Spanish author, Urraburu,[2] has been most frequently consulted. Much assistance has also been derived from Kleutgen's Philosophie der Vorzeit,[3] a monumental work which ought to have been long since translated into English. And finally, the excellent treatise in the Louvain Cours de Philosophie, by the present Cardinal Archbishop of Mechlin,[4] has been consulted with profit and largely followed in many places. The writer freely and gratefully acknowledges his indebtedness to these and other authors quoted and referred to in the course of the present volume.
General Introduction.
I. Reason of Introductory Chapter.—It is desirable that at some stage in the course of his investigations the student of philosophy should be invited to take a brief general survey of the work in which he is engaged. This purpose will be served by a chapter on the general aim and scope of philosophy, its distinctive characteristics as compared with other lines of human thought, and its relations to these latter. Such considerations will at the same time help to define Ontology, thus introducing the reader to the subject-matter of the present volume.
II. Philosophy: the Name and the Thing.—In the fifth book of Cicero's Tusculan Disputations we read that the terms philosophus and philosophia were first employed by Pythagoras who flourished in the sixth century before Christ, that this ancient sage was modest enough to call himself not a “wise man” but a “lover of wisdom” (φίλος, σοφία), and his calling not a profession of wisdom but a search for wisdom. However, despite the disclaimer, the term philosophy soon came to signify wisdom simply, meaning by this the highest and most precious kind of knowledge.
Now human knowledge has for its object everything that falls in any way within human experience. It has extensively a great variety in its subject-matter, and intensively a great variety in its degrees of depth and clearness and perfection. Individual facts of the past, communicated by human testimony, form the raw materials of historical knowledge. Then there are all the individual things and events that fall within one's own personal experience. Moreover, by the study of human language (or languages), of works of the human mind and products of human genius and skill, we gain a knowledge of literature, and of the arts—the fine arts and the mechanical arts. But not merely do we use our senses and memory thus to accumulate an unassorted stock of informations about isolated facts: a miscellaneous mass of mental furniture which constitutes the bulk of human knowledge [pg 002] in its least developed form—cognitio vulgaris, the knowledge of the comparatively uneducated and unreflecting classes of mankind. We also use our reasoning faculty to reflect, compare, classify these informations, to interpret them, to reason about them, to infer from them general truths that embrace individual things and events beyond our personal experience; we try to explain them by seeking out their reasons and causes. This mental activity gradually converts our knowledge into scientific knowledge, and thus gives rise to those great groups of systematized truths called the sciences: as, for example, the physical and mathematical sciences, the elements of which usually form part of our early education. These sciences teach us a great deal about ourselves and the universe in which we live. There is no need to dwell on the precious services conferred upon mankind by discoveries due to the progress of the various special sciences: mathematics as applied to engineering of all sorts; astronomy; the physical sciences of light, heat, sound, electricity, magnetism, etc.; chemistry in all its branches; physiology and anatomy as applied in medicine and surgery. All these undoubtedly contribute much to man's bodily well-being. But man has a mind as well as a body, and he is moreover a social being: there are, therefore, other special sciences—“human” as distinct from “physical” sciences—in which man himself is studied in his mental activities and social relations with his fellow-men: the sciences of social and political economy, constitutional and civil law, government, statesmanship, etc. Furthermore, man is a moral being, recognizing distinctions of good and bad, right and wrong, pleasure and happiness, duty and responsibility, in his own conduct; and finally he is a religious being, face to face with the fact that men universally entertain views, beliefs, convictions of some sort or other, regarding man's subjection to, and dependence on, some higher power or powers dwelling somehow or somewhere within or above the whole universe of his direct and immediate experience: there are therefore also sciences which deal with these domains, morality and religion. Here, however, the domains are so extensive, and the problems raised by their phenomena are of such far-reaching importance, that the sciences which deal with them can hardly be called special sciences, but rather constituent portions of the one wider and deeper general science which is what men commonly understand nowadays by philosophy.
The distinction between the special sciences on the one hand and philosophy, the general science, on the other, will help us to realize more clearly the nature and scope of the latter. The special sciences are concerned with discovering the proximate reasons and causes of this, that, and the other definite department in the whole universe of our experience. The subject-matter of some of them is totally different from that of others: physiology studies the functions of living organisms; geology studies the formation of the earth's crust. Or if two or more of them investigate the same subject-matter they do so from different standpoints, as when the zoologist and the physiologist study the same type or specimen in the animal kingdom. But the common feature of all is this, that each seeks only the reasons, causes, and laws which give a proximate and partial explanation of the facts which it investigates, leaving untouched and unsolved a number of deeper and wider questions which may be raised about the whence and whither and why, not only of the facts themselves, but of the reasons, causes and laws assigned by the particular science in explanation of these facts.
Now it is those deeper and wider questions, which can be answered only by the discovery of the more remote and ultimate reasons and causes of things, that philosophy undertakes to investigate, and—as far as lies within man's power—to answer. No one has ever disputed the supreme importance of such inquiries into the ultimate reasons and causes of things—into such questions as these, for instance: What is the nature of man himself? Has he in him a principle of life which is spiritual and immortal? What was his first origin on the earth? Whence did he come? Has his existence any purpose, and if so, what? Whither does he tend? What is his destiny? Why does he distinguish between a right and a wrong in human conduct? What is the ultimate reason or ground of this distinction? Why have men generally some form or other of religion? Why do men generally believe in God? Is there really a God? What is the origin of the whole universe of man's experience? Of life in all its manifestations? Has the universe any intelligible or intelligent purpose, and if so, what? Can the human mind give a certain answer to any of these or similar questions? What about the nature and value of human knowledge itself? What is its scope and what are its limitations? And since vast multitudes of men believe that the human race has been specially [pg 004] enlightened by God Himself, by Divine Revelation, to know for certain what man's destiny is, and is specially aided by God Himself, by Divine Grace, to work out this destiny—the question immediately arises: What are the real relations between reason alone on the one hand and reason enlightened by such Revelation on the other, in other words between natural knowledge and supernatural faith?