CLARK'S REFORMULATION OF THE CAPITAL CONCEPT 141
artificial, produced, goods and to include as capital anything
(or at least its value) that is the durable foundation of a use
that has value.
Very similar ideas were developed by Carl Rodbertus in the
thirties and forties, most significant because of the great influence
they exercised upon later thinkers in the period of developing
German state socialism after 1870. Especially Adolf Wagner
acknowledged his profound indebtedness to Rodbertus.® To
Wagner is due the much wider circulation and influence in the
last quarter of a century of these ideas which he restated and
endorsed.” Wagner credits Rodbertus with “the essential dis-
tinction between capital in the purely economic sense as any stock
of material agents and means of production, and capital in the
historico-legal sense as capital-possessions.” He cites the state-
ment of Knies that political economy uses capital in two senses,
as concrete means of production, and as a stock of goods acquired
by an owner. Both Wagner and Knies recognize the double
meaning of capital as a tool in economic processes (technological
sense) and as a source of private income (acquisitive sense), the
distinction on which so much of the thought of Thorstein Veblen
as well as of Karl Marx, seems to have been based. When Knies
says approvingly that what has been called capital is “funda-
mentally nothing but a mere abstraction,” * the expression might
be the original of Clark’s “entity,” “this abstract conception of
capital.” *
Clark, in common with all other Americans pursuing graduate
economic studies in Germany, must have become familiar with
these ideas. Yet why did no trace of them ever appear in the
writings of other students returning from Germany, or even in
Clark’s writings, until 1888? Is not the explanation to be found
in the fact that Americans went abroad with minds already cast
in the mold of the Ricardian-Mill “orthodox” scheme of dis-
tributive theory, and these concepts persisted. It was possible
for these students to acquire a zeal for displacing (or for supple-
' The ideas of Rodbertus on capital are scattered throughout his writ-
ings, but perhaps more systematically presented in his work Das Kapital,
written 1850-51 but published first in 1885 by A. Wagner and T. Kozak.
(Known to the writer only in the French translation, Paris, 1904.)
* See Wagner's Grundlegung, 3rd. ed., 1892, p. 307 ff.
* Knies, op. cit., p. 43.
‘ Clark, op. cit., p. 11.
