Abstract. Adam Smith defined economics as “the science of the nature and causes of the wealth of nations” (implicitly appealing – in reference to the “wealth” – to the “value”). Neo-classical theory views it as a science “which studies human behavior in terms of the relationship between the objectives and the limited funds that may have a different use of”. The main reason that turns the neo-classical theory (that serves as the now prevailing economic mainstream) into a tool for manipulation of the public consciousness is the lack of measure (elimination of the “value”). Even though the neo-classical definition of the subject of economics does not contain an explicit rejection of objective measures the reference to “human behavior” inevitably implies methodological subjectivism. This makes it necessary to adopt a principle of equilibrium: if you can not objectively (using a solid measurement) compare different states of the system, we can only postulate the existence of an equilibrium point to which the system tends. Neo-classical postulate of equilibrium can not explain the situation non-equilibrium. As a result, the neo-classical theory fails in matching microeconomics to macroeconomics. Moreover, a denial of the category “value” serves as a theoretical basis and an ideological prerequisite of now flourishing manipulative financial technologies. The author believes in the following two principal definitions: (1) economics is a science that studies the economic system, i.e. a system that creates and recombines value; (2) value is a measure of cost of the object. In our opinion, the value is the information cost measure. It should be added that a disclosure of the nature of this category is not an obligatory prerequisite of its introduction: methodologically, it is quite correct to postulate it a priori. The author concludes that the proposed definitions open the way not only to solve the problem of the measurement in economics, but also to address the issue of harmonizing macro- and microeconomics.