Metaphysics, in its strictest sense, is applied, as a term, to that department of philosopkt/ which has for its object the investigation of existences out of our- selves— " that knowledge of causes and principles which we should carry with us into every department of in- ([uiry." Liasmuch as mind cannot properly know what is not in contact with itself, the question, " What is the nature of our knowledge of the external world?" has been asked by philosophers, and answered in various ways ; and this is the great question of metaphysics, if the term is applied in a strictly historical sense. Among modern writers of note in the field of philosophy, Prof. Ferrier, in his Inslilules of Metaphysics (Edinb. and Loud. 1854, 12mo), accordingly occupies himself solely with the questions connected with knowledge, or the nature of our perception of an external world ; his ex- planatory title is. The Theory of Knowing and Being. On the other hand, the lately-deceased Scotch philoso- pher Mansel, in his article Metaphysics {Cyclopcedia Britannica, 8th ed. vol. xiv, s. v.), divided the subject into two parts — "Psychology, or the science of the facts of consciousness [which expresses the science of mind generally] as such ; and Ontology, or the science of the same facts considered in their relation to realities exist- ing without the mind" — that is, the problem of percep- tion or metaphysics in the narrower sense. " Meta- physics," says the writer of the article on that subject in the Edinburgh Cyclopcedia, "have been called the Eirst philosophy, or the Science of Sciences, as their ob- ject is to explain the principles and causes of all things existing, and to supply the defects of inferior sciences, which do not demonstrate, or sufficiently explain, their principles." Here we have a stiU further departure from our first and somewhat circumscribed sphere to the vast expanse of the department itself known as jM- losophy. Of the above two branches of philosophy or metaphysics, 7w^c/(ofo(7y(q.v.) investigates the faculties and operations of the humah mind, while ontology (q. v.) seeks to develop the nature and laws of real existence. The former deals with the phenomena of consciousness, the constitution of the mind, the laws of thought; the latter with the essential characteristics of being per se, the constitution of the universe, the laws of things. The former is descriptive, and the latter scientific meta- physics. "Metaphysics," says Sir William Hamilton {Lect. vii, p. 85), " in whatever latitude the term be taken, is a science, or complement of sciences, exclu- sively occupied with mind. Now the philosophy of mind— psychology or metaphysics, in the widest signifi- cation of the terms— is threefold, for the object it im- mediately proposes for consideration may be either, 1, Phenomena in general ; or, 2, Laws ; or, 3, Inferences and Pesidls. . . . Tlie whole of philosophy is the answer to these three questions: 1. What are the facts or phenom- ena to be observed? 2. What are the laws which reg- ulate these facts, or under which these ])henomena ap- pear? 3. What are the real results, not immediately manifested, which these facts or phenomena warrant us in drawing ?"
The great authority which Aristotle enjoyed in the Middle Ages, and the Uttle actual knowledge respect- ing the laws of existence, induced his followers to form from his philosophical fragments a system, which served as a canon for the philosophy of the time. The oldest commentators of Aristotle had directed their endeavors to this point; but metaphysics, as an independent sci- ence, was developed by the schoolmen of the Middle Ages (Thomas Aquinas, Duns Scotus, William Occam, and others). In the 17th centurj-, however, the meta- physics of the schoolmen was undermined by the intro- duction of a critical spirit of investigation. Lord Ba- con, More, Hobbes, appeared in England ; Th. Campa- nella, in Italy ; Des Cartes, in France, as adversaries of the Aristotelian school-philosophy. For details, see Phi- losophy.
As regards the origin of the name, the most recent discussions appear, on the whole, to confirm the com- monly-received opinion, according to which the term Metaphysics, though originally employed to designate a treatise of Aristotle, was probably unknown to that philosopher himself. It is true that the oldest and best of the extant commentators on Aristotle refers the in- scription of the treatise to the Stagyrite (Alexander, in Arist. Mefh. p. 127, ed. Bonitz) ; but in the extant writ- ings of Aristotle himself, though the work and its sub- ject are frequently referred to under the titles of the Ei?-st Philosophy, or Theology, or Wisdom (Asclcpius, apud Brandis Scholia, p. 519, b. 19 ; Bonitz, in A 7-ist. Metaph. p. 5), no authority is found for the latter and more popular appellation. On the whole, the weight of evidence appears to be in favor of the supposition which attributes the inscription ra iktci tci ^vaiKc'i to Andronicus Ehodius, the first editor of Aristotle's col- lected works. The title, as given to the writings on the first philosophy, probably indicates only their place in the collection, as coming after the 'physical treatises of the author (comp. Bonitz ad Arist, Aletaph. p. 3, 5). In this respect the term Metaphysics has been aptly compared to that of Postils ; both names signifying nothing more than the fact of something else having preceded. Shakespeare used metaphysical as synony- mous with suj)ernatui-al,