Adversus Homo Economicus: Critique of Lester’s Account of Instrumental Rationality

In Chapter 2 of Escape from Leviathan, Jan Lester defends two hypotheses: that instrumental rationality requires agents to maximise the satisfaction of their wants and that all agents actually meet this requirement. In addition, he argues that all agents are self-interested (though not necessarily egoistic) and he offers an account of categorical moral desires which entails that no agent ever does what he genuinely feels to be morally wrong. I show that Lester’s two hypotheses are false because they cannot accommodate weakness of will, because they are inconsistent with agency, which requires free will, because ends, obligations and values cannot be reduced to desires, and because maximisation is often not possible. Further, Lester’s claim that agents are self-interested is vacuous, his attempted reduction of moral behaviour to want-satisfaction fails, and his contention, that agents always do what they genuinely think to be morally required, seems untenable. A defence of freedom that depends on homo economicus is far from promising.