Use value () or value in use is a concept in classical political economy and Marxist economics. It refers to the tangible features of a commodity (a tradeable object) which can satisfy some human requirement, want or need, or which serves a useful purpose. In Karl Marx's critique of political economy, any product has a labor-value and a use-value, and if it is traded as a commodity in markets, it additionally has an exchange value, most often expressed as a money-price. Marx acknowledges that commodities being traded also have a general utility, implied by the fact that people want them, but he argues that this by itself says nothing about the specific character of the economy in which they are produced and sold. Origin of the concept The concepts of value, use value, utility, exchange value and price have a very long history in economic and philosophical thought. From Aristotle to Adam Smith and David Ricardo, their meanings have evolved. Smith recognized that commodities may have an exchange-value but may satisfy no use-value, such as diamonds, while a commodity with a very high use-value may have a very low exchange-value, such as water. Marx comments for example that "in English writers of the 17th century we frequently find worth in the sense of value in use, and value in the sense of exchange-value." With the expansion of market economy, however, the focus of economists has increasingly been on prices and price-relations, the social process of exchange as such being assumed to occur as a naturally given fact. In The Economic and Philosophic Manuscripts of 1844, Marx emphasizes that the use-value of a labour-product is practical and objectively determined; that is, it inheres in the intrinsic characteristics of a product that enable it to satisfy a human need or want. The use-value of a product therefore exists as a material reality vis-a-vis social needs regardless of the individual need of any particular person. The use-value of a commodity is specifically a social use-value, meaning that it has a generally accepted use-value for others in society, and not just for the producer. Marx's definition Marx first defines use-value precisely in A Contribution to the Critique of Political Economy (1859) where he explains: The concept is also introduced at the beginning of Das Kapital, where Marx writes, but in the extract below he holds it up as a critique of Hegel's liberal "Philosophy