call the soul, raw material, which receives productive power from the labor of the teacher! For a calculation of the money value of man in the different ages of life, see Statis. Journ. XVI, 43 ff. See, on the other hand, _Malthus_, Definitions, ch. 7; and _Rossi_, in the Journal des Economistes, VI, 113. Nor does the view of _Ganilh_, Systèmes d’Economie politique (1809), I, 243; of _Ad. Müller_, Concordia, 93 ff., 211; of _Hermann_, “Staatswirth” Untersuchungen, No. 3; of _Dunoyer_, Liberté du Travail, L. VI; of _Bastiat_, _Carey_ and others, who include pieces of land in themselves under the head of capital, seem to be better founded. _Hermann_ defines capital the durable basis of every utility possessed of value in exchange. _Schäffle_ reckons land as nature offers it to us, among _free_ goods. From the moment that labor and capital are spent upon it, it becomes immovable capital, but he concedes that it still preserves many essential points which distinguish it from other capital. (N. Œk. Theorie der ausschliessenden Absatzverhältnisse, 1867, 65 ff., 89 ff.) These differences appear to me to be still more important than that which land and capital have in common; especially as the historic development of their relations proceeds for the most part in opposite directions. Thus, for instance, as civilization advances, land is wont to become dearer and capital cheaper. How difficult would it be to introduce clearness into the ideas of _intensive_ and _extensive_ agriculture, if land were accounted capital! And it is not only always theoretically, but also very often, in practice, possible to separate the value of a given piece of land from the most durable capital-improvements (_Kapitalmeliorationen_) made on it. It is only necessary to call to mind the area of buildings. _ 270 Marx_ makes a very arbitrary assertion when he says that only the capital operating in trade, and even only that operating in trade where money is used as the instrument of exchange, can properly be called capital; and that, therefore, the modern biography of capital dates only from the 16th century, (Das Kapital I, 106 ff.) 271 See, on the other hand, _Wolkoff_, Lectures d’Economie politique rationelle, 167. _ 272 Hermann_ (II ed., 238 ff.) distinguishes especially _preparatory contrivances_ auxiliary to labor, such as stationary structures etc., vessels, tools, machines and instruments for measuring etc.