(from L. materia, matter). Philosophical doctrine that considers matter as the sole constitutive reality of the real world. According to this view, matter in its higher forms (organic matter) is capable of changing and developing. Therefore, sensation, consciousness and ideas are no more than expressions of matter in its most organized forms. Material existence is primary, while consciousness is secondary. The antagonistic division between “materialists” and “idealists” (*Idealism) was widely accepted, given its simpleness, by the narrative of modernity. Today, in light of the new conceptions of the human being and science, these postures are being subjected to extensive revision. As for the human and social sciences, many materialists consider the governing role of economic factors in the development of society as determining the interests and possibilities of human beings and organizing life and its events. For these exponents, the materialist concepts of the State and property, of war and the progress of nations, of the classes and class struggle, help identify the reasons for the opposition and conflicts and offer guidance in political praxis. At the same time, gross m. takes the power of the economic factors as absolute, starting from the principle of determinism and causal conditionality of all phenomena. The term m. came into use in the early seventeenth century as physical doctrine regarding matter, and in the early eighteenth century as antonym of philosophical idealism. In ancient Greek philosophy, the concept of prime matter was understood as the substance that could not be divided to the infinite. In the Middle Ages, Thomism saw in matter the potential and passive principle which, in union with substantial form, constitutes the essence of all bodies, remaining in the substantial transmutations under each succeeding form. Secondary matter was considered as being the substantial compound of raw material and form as substance; that is, as a subject apt for receiving an accidental determination. In modern times, until the arisal of Einstein’s theory of general relativity, matter was conceived as anything that was subject to the laws of gravity. Subsequently, in modern physics, the concepts of matter and energy draw closer together and at times are equated. In the philosophy of history, the conception of m. is applied to the doctrines that interpret the historical process by reducing it to the material causes, and consider that the social structure is determined before all else by economic necessities and laws.