Editing Marginalism (section)

=== Eclipse ===
In his 1881 work ''Mathematical Psychics'',<ref>[http://socserv.mcmaster.ca/econ/ugcm/3ll3/edgeworth/mathpsychics.pdf ''Mathematical Psychics'']</ref> [[Francis Ysidro Edgeworth]] presented the [[indifference curve]], deriving its properties from marginalist theory which assumed utility to be a differentiable function of quantified goods and services.  But it came to be seen that indifference curves could be considered as somehow ''given'', without bothering with notions of utility.

In 1915, [[Eugen Slutsky]] derived a theory of [[consumer choice]] solely from properties of indifference curves.<ref>[[Eugen Slutsky]]; "Sulla teoria del bilancio del consumatore", ''Giornale degli Economisti'' 51 (1915).</ref> Because of [[World War I|the World War]], the [[October Revolution|Bolshevik Revolution]], and his own subsequent loss of interest, Slutsky's work drew almost no notice, but similar work in 1934 by [[John Hicks]] and [[R. G. D. Allen]]<ref>Hicks, John Richard, and Roy George Douglas Allen; "A Reconsideration of the Theory of Value", ''Economica'' 54 (1934).</ref> derived much the same results and found a significant audience. Allen subsequently drew attention to Slutsky's earlier accomplishment.

Although some of the third generation of Austrian School economists had by 1911 rejected the quantification of utility while continuing to think in terms of marginal utility,<ref>[[von Mises, Ludwig Heinrich]]; ''[[Theorie des Geldes und der Umlaufsmittel]]'' (1912).</ref> most economists presumed that utility must be a sort of quantity.  Indifference curve analysis seemed to represent a way of dispensing with presumptions of quantification, albeit that a seemingly arbitrary assumption (admitted by Hicks to be a "rabbit out of a hat")<ref>Hicks, Sir John Richard; ''Value and Capital'', Chapter I. "Utility and Preference" §8, p. 23 in the 2nd edition.</ref> about decreasing marginal rates of substitution<ref name="hicks_vc">Hicks, Sir John Richard; ''Value and Capital'', Chapter I. "Utility and Preference" §7–8.</ref> would then have to be introduced to have convexity of indifference curves.

For those who accepted that marginal utility analysis had been superseded by indifference curve analysis, the former became at best somewhat analogous to the [[Bohr model|Bohr model of the atom]]—perhaps pedagogically useful, but "old fashioned" and ultimately incorrect.<ref name="hicks_vc" /><ref name="samuelson">Samuelson, Paul Anthony; "Complementarity: An Essay on the 40th Anniversary of the Hicks-Allen Revolution in Demand Theory", ''Journal of Economic Literature'' vol 12 (1974).</ref>