Pantaleoni and Weinberger Accused Menger of Plagiarizing Gossen et al. But Menger Did Not Approve of Gossen, Rejecting His Purely Hedonistic Approach, the Application of Mathematics to Psychology, etc.

The new ideas of Menger, Jevons, and Walras were not grafted on the work already done by the early marginalists. The three discoverers were stimulated by some minor writers whom the historians of economic thought usually neglect. Some authors are suspicious of this overflow of discoveries and declare positively that at least Menger must have committed plagiarism.

Maffeo Pantaleoni and Otto Weinberger believed that Menger had read at least Gossen and Mangoldt before he published his discoveries and had concealed this knowledge from his readers. In the Hitotsubashi library, new facts have been discovered which make it unlikely that Menger had copied either author. Menger, indeed, had studied Julius (Gyula) Kautz, who is the earliest author who mentions Gossen (1858), and Menger underlined the two Gossen quotations. But it is still very doubtful that Menger had read Gossen before he finished his Principles. Menger had bought his copy of Gossen on May 8, 1886. The pages are marked in many places, and Menger always did this when he studied an author for the first time. Menger did not approve of Gossen, rejecting his purely hedonistic approach, his emphasis on labor, and the application of mathematics in the realm of psychology. It is not very probable, to say the least, that a writer would copy another author whose methods and findings he does not consider acceptable.

--Emil Kauder, A History of Marginal Utility Theory (Princeton, NJ: Princeton University Press, 1965), 81-82.