Even if the concept of equilibrium has taken different theoretical and epistemological forms on its journey from classical economics, via the marginalists of the nineteenth century, to twentieth-century neoliberalism, these versions share a limited spectrum of basic assumptions. They assume that all market players are interested in maximizing profit or use-value, that a self-regulating relationship between different quantities, forces and other factors obtains, that exchange mechanisms operate most effectively when arbitrary intrusions and interventions are kept to a bare minimum, and hence that the market should be seen as an exemplary arena for the clarification of otherwise inscrutable and opaque forms of social interaction.
Joseph Vogl, The Specter of Capital (Stanford: Stanford University Press, 2015), p. 35.
It is possible to define the interest of a person in such away that in every single decision they make they are seen to be following their own interests.
Amartya Sen, “Rational Fools: A Critique of the Behavioral Foundations of Economic Theory,” in The Self and the Political Order, ed. Tracy B. Strong (New York, 1992), p.121.
Precisely because human beings are asocial — this is how the surprising argument goes — they help contribute to social order; precisely because they are unreliable, they can be integrated into society as reliable, known quantities. How is this possible? By what mechanism can lawfulness be produced from anomic beings? What dynamic is at play here and what is its overall function in the system? Here too the answers given by English empiricists, French moralists, and German social engineers coincide in one essential point: all these affective dynamics come together in the mechanism of self-interest. At the heart of all (mis)deeds and passions, all desires and inclinations, lies an irreducible element which, since the seventeenth century, has gone by the name of “interest” or “self-interest.” The concept of (self-)interest probably originated in raison d’état or national interest before passing into social theory […] [p.21] Even the vilest cravings and most heated passions are stabilized by a trace element of self-interest that dictates the choice of the more pleasant, less painful option […] It is in self-interest that the inclinations and passions of all parties meet, and it is precisely in their pursuit of that interest that the social and political laws of nature are revealed.
Joseph Vogl, The Specter of Capital (Stanford: Stanford University, 2015), p.20.