CLARK'S REFORMULATION OF THE CAPITAL CONCEPT 151 
capital and income as “modes of measuring” which Hadley had 
come to believe “is almost as important as the distinction between 
public and private wealth” * which he had presented in his essay 
of the year before. This new distinction is, however, certainly 
more than a mere detail; it introduces into Hadley’s earlier clear 
and simple thought of capital as the value of rights of individual 
ownership, a different idea of a stock of wealth ® as contrasted 
with a flow of wealth. The latter was pretty clearly Fisher's own 
idea at that time, as appeared in his contemporary articles. In 
these Fisher presented this distinction between a “stock,” or a 
“fund,” and a “flow,” or a “stream,” as the one essential test of 
capital, as he conceived it. He is intent (not as was Hadley) on 
distinguishing capital as valuation from wealth as objects (for 
he thinks of both simply as material) but in distinguishing income 
as a flow of things from wealth as a fund, reservoir or stock of 
things. There is not a hint in Fisher's definitions that capital 
consists of “rights” expressed in terms of monetary valuation, or 
financially, or of its being a sum of purchasing power, a business 
investment concept. Fisher specifically objects to Clark’s 
expression of the amount of true capital in terms of price, instead 
of by physical measurements. However, as soon as he attempts 
to discuss the percentage rate of flow, he assumes the measurement 
of both stocks and streams in monetary terms, for in no other 
way could a percentage appear. Fisher's contrast was that 
between a stock and a stream of the “very same commodities.” * 
The present writer soon afterward ° sought to show that this view 
was untenable in that it overlooked the durative nature of many 
of the objects comprised in Fisher's material “capital,” and 
involved the erroneous assumption that all indirect agents 
eventually appear in substance as direct (enjoyable) goods. 
However, when Fisher next expounded his definition, though he 
referred in no way to this criticism, he introduced alongside of 
the old distinction a new one designed to obviate the difficulty 
“It would be a more accurate description of this distinction to say, 
using Hadley’s own phrases: between public wealth as the sum of the 
“means of enjoyment” or “means of happiness,” in existence, and private 
capital as the value of individual property rights. 
Matera objects by Fisher's definition, Nature of Capital and Income, 
Ps Economic Journal, Vols. 6 and 7, 1896, 1897. A number of references 
to J. B. Clark’s ideas occur in the three articles. 
* Op. cit., Vol. 6 (1896), p. 514. 
* See Quarterly Journal of Economics, Vol. 15 (1900), p. 19.