metaphysics (mĕtəfĬz´Ĭks), branch of philosophy concerned with the ultimate nature of existence. It perpetuates the Metaphysics of Aristotle, a collection of treatises placed after the Physics [Gr. metaphysics=after physics] and treating what Aristotle called the First Philosophy. The principal area of metaphysical speculation is generally called ontology and is the study of the ultimate nature of being. However, philosophical theology and cosmology are also usually considered branches of metaphysics. In the history of philosophy there have been many great metaphysical systems. One of the most carefully constructed systems is that of the scholastic philosophy (see scholasticism), which essentially is based on Aristotle's metaphysical system. In the 17th cent. the great rationalistic systems of René Descartes, Baruch Spinoza, Nicolas Malebranche, and G. W. von Leibniz were developed. They were followed in the 18th cent. by Immanuel Kant's critical philosophy, which demonstrated the impossibility of a scientific metaphysics. This was in turn succeeded by the metaphysics of German idealism (of J. G. Fichte, Friedrich von Schelling, and G. W. F. Hegel). Since the middle of the 19th cent. the dominant philosophical trend has been in the direction of positivism, which denies the validity of any metaphysical assertion. This is clearly reflected in the contemporary movement called logical positivism. A revival of interest in metaphysics since 1950 has been sparked by P. F. Strawson, whose descriptive metaphysics is an attempt not to construct a new metaphysical system but to analyze the metaphysical systems that already inform prevailing modes of thought.
See D. W. Hamlyn, Metaphysics (1984); B. Aune, Metaphysics (1985); D. H. Mellor, Matters of Metaphysics (1991).