MATERIALISM, the philosophical theory that everything which exists is ultimately mate rial in nature, or that whatever is real can be derived and explained in accordance with the laws of material phenomena. This, of course, carries with it a denial of the reality of any finite or infinite spirit as an immaterial sub stance and a repudiation of all forms of ideal ism, which uses thought or intelligence as a principle of explanation. Materialism, however, may be more or less explicit and may maintain either absolutely, or with various modifications, the primary and all-embracing character of mat ter. Thorough-going materialism asserts that nothing exists but physical bodies and physical processes. What are called immaterial sub stances and processes it either declares to be unreal, or explains away as ultimately not dif ferent in nature from physical substances and processes. Moreover, for materialism of this consistent and uncompromising type, matter is dead and moved only by mechanical forces. It has no side,« and the laws which it obeys are the expressions of a blind physical necessity. This extreme view is perhaps no longer maintained by any philosophical thinker of reputation, but an various modified forms it still exists as a tendency to subordinate mental phenomena to physical processes. The more Important of these modifications and limitations may be brought under the following heads. (1) The subordination of mental phenomena, while still acknowledging more or less explicitly their distinctive character, to physical, and especially to physiological processes as their determining causes. This position does not usually avoid any of the practical consequences of mate rialism, and always tends, when thought out, to revert to the strict ontological form of the theory. For it is an easy transition from the view that physical processes are able to cause mental modifications to the opinion that the mind is not fundamentally different in char acter from the matter which affects it. (2)
The view that matter is not a dead lump or mass that moves only when acted upon by some external body, as the older theories as sumed, but that every particle of matter— every atom, or it may be every cell — is ((con joined with a soul," or has a ((psychical side? or a certain element of mind-stuff?' By thus introducing an element which is dif ferent in character and in mode of operation from matter, this theory seems to differentiate itself in principle from materialism. Never theless, it is usually assumed tacitly by repre sentatives of this modern Hylozoism that within the atom or cell the material side is the primary and determining element, while the physical is secondary and subordinate. More over, the whole mode of conception usually remains at the mechanical stage, since the im material element never comes to its rights as an ideal principle, but is conceived as a mere moving force or instinct, and also since it is assumed that the complex mental life can be built up by the composition of psychic elements just as a material body is constituted by the combination of its parts. (3) The position of energism. Recently an attempt has been made to find in energy an ultimate reality in terms of which both mental and material phenomena may be expressed. It cannot be maintained, however, that the conception of energy has yet been clearly defined, nor is everyone prepared to accept the assurance of Professor Ostwald, the chief representative of the theory, that energy is the concrete reality which we directly experience. To many it may appear to be merely an abstract built out of the data of experience. Apart from this difficulty, however, energism does not avoid materialism merely by dematerializing its fundamental principle. In Professor Ostwald's hands, it ap pears to remain essentially materialistic; since the conceptions employed and the laws which the transformations of energy obey are those of physical science.