Materialism is the theory of the world which professes to find in matter (monistic or philosophical materialism), or in material entities (atomistic materialism), or in material qualities and forces (scientific or physical materialism), a complete explanation of all life and existence whatsoever. Early philosophies are generally either theogonies or cosmogonies. Cosmogonies tend to postulate animated or living matter (hylozoism). Out of the earliest hylozoistic philosophemes of the Ionic school in Greece arose the atomistic materialism of Leucippus and Democritus, explaining the cosmos as an aggregation and segregation of ultimate indivisible material entities or atoms. The atomic theory of Democritus became the basis of the sensationalistic psychology and ethic of Epicurus, and was transmitted in the glowing verses of Lucretius' great didactic poem, De Rerum Naturâ, on to the later Roman period. Materialism as a basis for scientific research we find revived in history wherever a movement arose in favour of the methods and aims of experimental or natural science, as in the Renaissance period in Europe generally. Gassendi, though, it is who must be regarded as the renewer par excellence, in modern times, of systematic materialism. He developed the doctrine of Democritus, by endowing the atoms with force and even with sensation. Lamettrie, by his materialistic account of the functions of the mind, prepared the way in France for the comprehensive materialism of Baron Holbach, whose Système de la Nature is the chef-d'œuvre of French materialism. In Holbach materialism reaches its high-water mark. Applying materialism to anthropology, he seeks to show that man is only a physical being, and that morality or virtue is independent of the supports of positive religion and of theism.
The empirical method of Bacon and Locke, taken along with some things Locke said about matter being possibly made to think, and eagerly caught up by men like Voltaire, had countenanced in England as well as in France a materialistic treatment of the mental and spiritual powers of man, as in the works of Hobbes, Hartley, and Priestley. In Germany philosophy was in the main idealistic and speculative until the death of Hegel, but Vogt about 1850 applied the principles of materialism to psychology, holding that physiology pronounced definitely and categorically against the idea of individual immortality, as indeed against all notions founded on the idea of the independent existence of the soul. Moleschott and Büchner are associated with
Vogt as upholders of materialism. Büchner's Kraft und Stoff ('Force and Matter') is the Bible of German materialism. Feuerbach and Strauss may be mentioned as philosophers who exchanged the spiritualistic monism of Hegel for materialistic monism.
The form in which materialism now appears has been determined by the doctrine of evolution. Materialism indeed might be said to have been absorbed in the wider theory of evolution, which goes beyond the mere antitheism or atheism of materialism, and seeks positively to show how the diversities and differences in the world can be accounted for by natural as opposed to supernatural or creative process. Haeckel is perhaps the most prominent upholder of the Darwinian hypothesis on the Continent.
Materialism may be examined from many points of view. (1) Materialism is scientific realism. It believes, i.e., in real physical entities, such as atoms and forces, and spaces and times. Now a belief in atoms leads, in physics, in chemistry, and in astronomy, to insoluble contradictions: atoms, for example, for physical purposes must be at once absolutely impenetrable and unalterable, and yet absolutely elastic and alterable. It would be more correct, in fact, to reduce matter to forces than to atoms, as many theorists have done. But it is difficult to think of forces existing without some sort of substrate. Spaces and times too are not physical things. Thus science is full of hypotheses; nor can it dispense with hypotheses. Complete physical realism or materialism is, in short, theoretically impossible. (2) Even granting—which in strictness we cannot—the existence of 'mere matter,' science has as yet found insuperable difficulty in passing from unorganised to organised matter. (3) Psychology has as yet been unable to regard organic states as accounting for psychical or mental states. The two are totally different, and, though correlated, cannot be said to be causally connected. (4) Materialism cannot furnish a complete or consistent ethical theory. If man is entirely the product of natural forces, and in fact the sport of natural forces, it is meaningless to think or speak of him as morally obliged either to follow or to resist nature. Man not only follows and resists nature, but in mechanical and artistic construction commands and anticipates and surpasses nature. Of course to materialism the belief in human freedom, which practically makes history, is an illusion, but it is difficult to see how on the materialistic hypothesis even this illusory belief could have arisen. (5) Although materialistic evolution may succeed in showing that we ought not to regard certain natural adaptations and productions as special and final creations, it cannot and does not avoid the question of teleology. Neither hylozoism nor mechanism, nor unconscious selection and adaptation accounts for that relativity of everything to everything, which is really what at bottom is meant by teleology. There must be a world-soul or world-thought for whom the universe is realised end. (6) There is the philosophical question about mere matter. It has again and again been confessed by scientists as well as by philosophers that by matter can only, in the last resort, be meant what J. S. Mill calls the permanent possibility of sensation. There is in fact no object (or objective thing) without a subject (or consciousness). If the materialist at once reply that there is no subject without an object, he is in the right as against the thesis. The idealist, in short, and the materialist are in the right as against each other. Subject and object imply each other. We cannot begin with either in order to explain from it the other.
Materialism brings prominently before us that side of the universe which is compassed by the methods of physical science. But physical science, like (say) economic or theological or mental science, takes a one-sided or 'abstract' view of experience. All sciences 'abstract' from the concrete whole of experience contain facts which they propose to investigate in detail. Physicists, like metaphysicians and theologians, are apt to become dogmatical about spheres of inquiry of which they know professedly nothing.
BIBLIOGRAPHY.—Text-books of Materialism which have not already been mentioned are: Gassendi, De Vita, Moribus, et Doctrinis Epicuri (Leyden, 1647); Lamettrie, L'Homme Machine (Leyden, 1748); Haeckel, Natürliche Schöpfungsgeschichte (1868; Eng. trans. 2d ed. 1875-76); Wiener, Grundzüge der Weltordnung (1863-69); and Huxley's Address at Belfast, 1875. For an examination of Materialism, see any account of Kant's Critical Philosophy; or the statement of Dogmatism given in Fichte, by Adamson (Blackwood's 'Philosophical Classics'); also As regards Protoplasm, by Dr Hutchison Stirling; Concepts of Modern Physics, by J. B. Stalls, containing a sifting examination of the atomic theory; Reign of Law, by the Duke of Argyll; and St George Mivart's books. The best history of Materialism is Lange's Geschichte des Materialismus (Eng. trans. 1878-81).