Leo Schönfeld-Illy, Grenznutzen und Wirtschaftsrechnung — Summary

This is a single-author theoretical economic treatise on marginal utility and economic calculation. Its scope is conceptual rather than historical: Schönfeld-Illy asks what marginal utility is once it is placed inside the actual procedure of economic choice. The central thesis is that marginal utility should not be understood as a measurable quantity of pleasure, but as a functional concept arising from practical economic calculation: it helps actors abbreviate a complex sequence of partial decisions about concrete goods.

Schönfeld-Illy begins from a critique of utility measurement. Economic theory may speak as if utility were a magnitude, but ordinary economic action does not proceed by measuring psychic units of satisfaction.

Die Beobachtung der wirtschaftlichen Wirklichkeit lehrt uns aber, daß die Wirtschaftssubjekte den Nutzen nicht messen.

English translation: But the observation of economic reality teaches us that economic agents do not measure utility.

This does not lead him to discard utility theory. Rather, he redefines what “greater” utility means within calculation. A higher utility is not a larger measurable quantum; it is a priority in disposition, a rank that directs action.

Größer sein heißt für einen Nutzen vom Standpunkt der Wirtschaftsrechnung: wirtschaftlichen Vorrang haben.

English translation: For a utility, to be greater from the standpoint of economic calculation means: to have economic precedence.

The work therefore converts marginal utility from a quasi-psychological magnitude into a category of ordering and choice. Economic calculation remains oriented toward a maximum, but the “maximum” is not produced by adding measured utilities. It is the formal name for the aim of arranging scarce goods so that the total economic result is best.

Sie ist, mathematisch charakterisiert, ein Maximumproblem des Nutzens; die veränderliche Nutzengröße, um deren Maximum es sich bei diesem Problem handelt, ist durch den Zweck des Wirtschaftens bezeichnet: den Gesamtwirtschaftsnutzen zu einem Größten, einem Maximum, zu machen.

English translation: It is, characterized mathematically, a maximum problem of utility; the variable utility magnitude, whose maximum is at issue in this problem, is designated by the purpose of economic activity: to make the total economic utility a greatest, a maximum.

The structure of the argument moves from this general account of economic calculation to the specific status of marginal utility. Schönfeld-Illy distinguishes between a theoretically complete procedure, advancing from partial decision to partial decision, and the shortened procedure actually used in practice. Marginal utility belongs chiefly to the latter. It is the conceptual tool by which the actor avoids having to reconstruct the whole order of uses at every step.

Die allgemeine Problemstellung des Grenznutzens, die Frage nach seinem eigensten, aus seinem Dienst in der Wirtschaftsrechnung entspringenden Wesen ist in der Frage enthalten: wie das theoretisch entwickelte, das von Teilentscheidung zu Teilentscheidung vorschreitende Verfahren der Wirtschaftsrechnung in seiner Durchführung abgekürzt werden kann und in praxi abgekürzt wird.

English translation: The general problem of marginal utility—the question concerning its innermost essence, arising from its service in economic calculation—is contained in the question: how the theoretically developed procedure of economic calculation, advancing from partial decision to partial decision, can be abbreviated in its execution and is in practice abbreviated.

This is the book’s key conceptual move: the marginal principle is not merely one more element in a complete utility scale, but an abbreviation of the full calculative process. Schönfeld-Illy separates the “Teilnutzenordnungen” or utility scales from the practical operation of marginal utility itself. The former belong to a theoretical reconstruction of calculation; the latter belongs to actual decision.

Begriff und Anwendung des Grenznutzens gehören also unserer Meinung nach essentiell dem Bereich des abgekürzten praktisch geübten Verfahrens der Wirtschaftsrechnung an, Begriff und Anwendung der Teilnutzenordnungen (bzw. der Nutzenskalen) als solcher jedoch dem Bereich der theoretisch entwickelten unabgekürzten, von Teilentscheidung zu Teilentscheidung vorschreitenden Wirtschaftsrechnung.

English translation: In our view, therefore, the concept and application of marginal utility belong essentially to the sphere of the abbreviated, practically employed procedure of economic calculation, whereas the concept and application of partial utility orderings (or utility scales) as such belong to the sphere of the theoretically developed, unabbreviated economic calculation that proceeds from partial decision to partial decision.

The relevance of the treatise lies in this clarification. Schönfeld-Illy preserves the subjectivist foundation of value theory while avoiding the fiction that utility is directly measurable. Goods matter economically because of their concrete subjective uses, but those uses govern choice through ranking, substitution, and priority rather than through cardinal measurement.

Die beim Wirtschaften über die Güter zu treffenden Verfügungen werden von dem subjektiven konkreten Nutzen dieser Güter regiert.

English translation: The dispositions to be made in economic action over goods are governed by the subjective concrete utility of these goods.

In this sense, Grenznutzen und Wirtschaftsrechnung is a theory of how marginal utility functions inside calculation. Its argument links utility, scarcity, and decision by showing that economic action aims at an ordered maximum, yet proceeds through practical shortcuts. Marginal utility is thus neither a psychological datum nor a mere mathematical symbol; it is the operative form in which subjective concrete utility becomes economically calculable.