Oskar Morgenstern, John von Neumann, 1903–57 (1958)

Oskar Morgenstern’s journal obituary presents von Neumann’s significance for economics within an account of his exceptional scientific range. Its central claim is historical as well as commemorative: sustained engagement by a mathematician of this stature opened possibilities for economic theory that the profession was only beginning to recognize. The essay moves from biography through pure and applied mathematics to an extended interpretation of game theory and the expanding-economy model, before considering automata and closing with personal recollections.

He was the first of the great, creative mathematicians who gave prolonged attention to economic and social science.

This claim frames economics as an important destination of von Neumann’s intellectual activity, without making it the centre of his career. Morgenstern sketches his precocious education in Budapest and Zürich, his association with Hermann Weyl, his European academic appointments, and his move to Princeton in 1930. His subsequent positions at the Institute for Advanced Study and the United States Atomic Energy Commission establish the conjunction of theoretical achievement and public responsibility. The catalogue of mathematical contributions—from set theory and operator theory to the ergodic theorem and continuous geometry—supports the obituary’s insistence that his distinction extended across fields normally beyond any individual’s command.

Morgenstern nevertheless avoids assigning a definitive hierarchy to these achievements. Operator theory may prove especially consequential, while the mathematical foundations of quantum mechanics exemplify von Neumann’s ability to clarify a field’s conceptual structure. In Morgenstern’s account, von Neumann distinguished quantum mechanics in kind from classical and statistical mechanics. This distinction later supplies an analogy for the depth of change potentially introduced by game theory, though the obituary explicitly limits that comparison.

The connection between pure mathematics and applications rests on a philosophy of scientific discovery:

Therefore close contact with empirically given problems should guide mathematical research.

Applications are thus sources of mathematical invention, not merely occasions for using established techniques. Morgenstern links this conviction to work in physics, astrophysics, meteorology, and economics, and to the computational orientation that made von Neumann central to electronic computing. Numerical methods also generated theoretical questions about the limits of computation and the length of proofs. The Monte Carlo method, developed with S. Ulam, and computer-assisted meteorology illustrate this reciprocal movement between practical problems, mathematical innovation, and new scientific capabilities.

The economic discussion concentrates on games of strategy and the expanding economy. Morgenstern traces the minimax theorem from the 1928 game-theory paper to its reappearance in the economic-equations paper, first published in 1937. He treats that recurrence as evidence of a deeper connection still awaiting clarification. The Theory of Games and Economic Behavior (1944) then marks the development of a research programme whose significance depends on changing the conception of an economic problem itself.

In strategic interaction, an outcome depends on variables controlled by several individuals, possibly together with chance. Their interests may conflict or coincide. Individual optimization cannot therefore be understood independently of others’ choices:

There is here, therefore, given no ordinary maximum problem at all but a peculiar mixture of such—a conceptual situation entirely different from that studied by present-day economics.

For Morgenstern, this is the decisive conceptual move. The mechanical analogy inherited by economics gives way to optimal strategy, and rational behaviour becomes a problem of interdependent action. The fundamentally combinatorial character of these situations demands mathematical logic, set theory, and related methods rather than reliance on conventional analysis and differential equations. Cooperation and the non-additivity of value become central questions. The numerical treatment of utility, defined up to a linear transformation, likewise arises from behaviour directed toward an uncertain future, while marginal utility in its familiar simple form is abandoned.

These claims are prospective rather than declarations of an accomplished disciplinary revolution. Should game theory prevail, Morgenstern argues, the break would be deeper than the marginalist changes of the 1870s, which remained within an older conceptual framework. Yet the analogy with quantum mechanics must not obscure economics’ comparatively undeveloped condition: he reports von Neumann’s conviction that economic theory stood closer to physics before Newton.

The expanding-economy model offers a second methodological turning point. Under restrictive assumptions, it establishes the possibility of uniform expansion and the equality of expansion and interest rates.

One of the characteristics of the model of signal importance to the economist is that it deals with inequalities rather than equations.

The significance lies in replacing equation-counting as a supposed test of equilibrium’s existence. Connections with linear programming, subsequent generalizations, and dynamic input-output models interpreted as special cases demonstrate the model’s continuing fertility.

The final sections extend this portrait to automata: reliable systems constructed from unreliable components, self-reproducing machines, and neurological questions opened new relations between mathematics, organisms, and computation. Unfinished writings make von Neumann’s death a loss of developing ideas as well as completed achievements. Personal memories of his intuition, generosity, extraordinary memory, humour, and loyalty conclude the obituary. Its relevance rests above all on its account of economics as a source of new mathematics—and of strategic interaction as a challenge to the discipline’s inherited concepts, not simply an additional technique.