Upshots for Other Debates

This chapter explores and draws out the consequences of both the dualist view of rationality defended in Part I and the theory of structural rationality defended in Part II for a series of standing debates in (meta)ethics and epistemology—including debates about moral rationalism, rational choice theory, higher-order evidence, the normativity of logic, epistemic permissivism, and conditionalization. It also considers and criticizes some popular ways of trying to account for the existence and force of coherence requirements in the formally inclined philosophical literature—namely, Dutch book and money pump arguments and accuracy dominance arguments.

A Simpler, More Compelling Money Pump with Foresight

One might think that money pumps directed at agents with cyclic preferences can be avoided by foresight. This view was challenged two decades ago by the discovery of a money pump with foresight, which works against agents who use backward induction. But backward induction implausibly assumes that the agent would act rationally and retain her trust in her future rationality even at choice nodes that could only be reached if she were to act irrationally. This worry does not apply to BI-terminating decision problems, where at each choice node backward induction prescribes a move that terminates further action. For BI-terminating decision problems, it is enough to assume that rationality and trust in rationality are retained at choice nodes reachable by rational moves. The old money pump with foresight was not BI-terminating. In this paper, we present a new money pump with foresight, one that is both BI-terminating and considerably simpler.

Non-transitive Better than Relations and Rational Choice

This paper argues that decision problems and money-pump arguments should not be a deciding factor against accepting non-transitive better than relations. If the reasons to accept normative standpoints that entail a non-transitive better than relation are compelling enough, we ought to revise our decision method rather than the normative standpoints. The paper introduces the most common argument in favor of non-transitive better than relations. It then illustrates that there are different ways to reconceptualize rational choice so that rational choice is possible also when the relevant better than relation is non-transitive.

The Impotence of the Value Pump

Many philosophers have argued that agents must be irrational to lose out in a ‘value pump’ or ‘money pump’. A number of different conclusions have been drawn from this claim. The ‘Value Pump’ (VP) has been one of the main arguments offered for the axioms of expected utility theory; it has been used to show that options cannot be incomparable or on a par; and it has been used to show that our past choices have normative significance for our subsequent choices. In this article, I argue that the fact that someone loses out in a value pump provides no reason to believe that they are irrational. The VP is impotent.