METAPHYSICS, a name originally applied to those books of Aris totle which followed his Physics,' and which his editors called 'the books after the Physics' (aerit .ra 0.0-.0. In modern times the word has been variously applied, and seems to assume quite a distinct mean ing as employed by different authors. With the Germans, metaphy sics is'a science purely speculative, which soars beyond the bounds of experience. The objects of this science are supersensual ideas, unat tainable by experience, and the difficulty of defining the word lies iu the circumstance that the very knowledge of the ideas sought requires some proficiency in the study. Hence to one altogether unacquainted with speculative philosophy it is almost impossible to explain the meaning of the word " metaphysics" as used in this sense. The very possibility of a science beyond experience has been denied by a great number of philosophers, and many works called metaphysical should rather be termed inquiries into the possibility of metaphysics. Thus Kant's celebrated work, the Kritik der reinea Vernunft, is a mere inquiry into the possibility of a theoretical science of things beyond experience, which terminates with a denial of such possibility ; and hence some modern philosophers have considered Kant as no metaphy sician, but as a critic of the mental faculties, whose labours were to be the precursors of a new system of speculation. On the other hand, a work like Spinoza's " Ethics" is purely metaphysical. He assumes the possibility of his science, and, proceeding from a number of axioms, speculates accordingly. Those who deny the possibility of metaphysics deny even the right to assume any axioms as applicable to a sphere beyond experience ; and those who did assume them, as Spinoza, Liebnitz, and Wolf, were called by the Kautians dogmatists, in opposi tion to their own appellation of critics. The great point to be established prior to metaphysical speculation is the identity, or at least the necessary concurrence, of thought and being. This once established,
speculative inquiry may proceed, as the results of logical investigation must in such a case, of course, concur with the nature of being itself ; but the sceptics always deny the right of assuming such identity or concurrence, while on the other band different theories have been adopted to prove them, such as those of harmony between body and spirit,—of the non-being of body altogether, except as an affection of spirit,—of an absolute identity between thought and being, &e. It may be as well to observe that the critical philosophy, which assumes nothing but the " I" or " ego," and the laws of thought (Fichte deduc the latter from the axiom, " I am I"), has Descartes for its author, whose " Cogito, ergo sum," lies at the basis of most modern systems. [DESCARTES, in BIOO. DIV.] In England, the word metaphysics is usually applied to denote the philosophy of mind, as ,distinguished from that of matter. This science treats of the association of ideas, memory, and various pheno mena of mind ; and as it consists merely in collecting facts and making inductions like any other experimental science, its possibility is no more questionable than that of chemistry or electricity. How ever, Locke's ' Essay on the Human Understanding; as a denial of any source of knowledge other than experience, may be put 'at the side of Kant'e Kritik; as containing inquiries of similar nature, though the results be different ; Berkeley's Idealism' may be compared with the " Wissenschaftslehre' of Fichte, and the Common-sense theory of Reid with the views of Jacobi. The philosophy of mind as an experimental science has been chiefly treated by the modern Scotch philosophers, among whom the late Sir W. Hamilton holds a high place.