metaphysics

Branch of philosophy that deals with first principles, in particular ‘being’ (ontology) and ‘knowing’ (epistemology), and that is concerned with the ultimate nature of reality. It has been maintained that no certain knowledge of metaphysical questions is possible.

Epistemology, or the study of how we know, lies at the threshold of the subject. Metaphysics is concerned with the nature and origin of existence and of mind, the interaction between them, the meaning of time and space, causation, determinism and free will, personality and the self, arguments for belief in God, and human immortality. The foundations of metaphysics were laid by Plato and Aristotle. St Thomas Aquinas, basing himself on Aristotle, produced a metaphysical structure that is accepted by the Catholic Church. The subject has been advanced by René Descartes, Baruch Spinoza, Gottfried Leibniz, George Berkeley, David Hume, John Locke, Immanuel Kant, G W F Hegel, Arthur Schopenhauer, and Karl Marx; and in the 20th century by Henri Bergson, F H Bradley, Benedetto Croce, John McTaggart, Alfred North Whitehead, and Ludwig Wittgenstein.