… is from page 93 of the 1985 NYU Press edition of the 1963 English-language translation of Carl Menger’s 1883 Investigations Into the Method of the Social Sciences with Special Reference to Economics (Untersuchungen über die Methode der Sozialwissenschaften und der politischen Okonomie insbesondere) (footnote deleted; original emphases):
The nation as such is not a large subject that has needs, that works, practices economy, and consumes; and what is called ‘national economy’ is therefore not the economy of a nation in the true sense of the word. ‘National economy’ is not a phenomenon analogous to the singular economies in the nation to which also the economy of finance belongs. It is not a large singular economy; just as little as it is one opposed to or existing along with the singular economies in the nation. It is in its most general form of phenomena a peculiar combination of singular economies.
Thus the phenomena of “national economy” are by no means direct expressions of the life of a nation as such or direct results of an “economic nation.” They are, rather, the results of all the innumerable individual economic efforts in the nation, and they therefore are not to be brought within the scope of our theoretical understanding from the point of view of the above fiction. Rather the phenomena of “national economy,” just as they present themselves to us in reality as results of individual economic efforts, must also be theoretically interpreted in this light.