Rationality as self-interest versus rationality as present aims.

Neoclassical theory of economics has two main interpretations of its concept of rationality, internal cognitive consistency and the maximization of self-interest. Self-interest, unlike consistency, is normally an added characterization of an agent who is already formally characterized as choosing in accordance with some ranking. Nevertheless it is implicitly present in much of traditional economic theory. For example, in general equilibrium theory, in establishing the correspondence of equilibrium with Pareto optimality. Self-interest may also be added to formal consistency as a spice of "realism." It is often introduced, not in the formal axiomatization, but by an appeal to intellectual history. Even economist Adam Smith's conception of industrial capital class was based on accumulation of self-interest. A defense of self-interest today must confront present challenges and will take little comfort from a deep study of what Smith actually had written.