UC Santa Barbara

Ambitious presumptivism says that all our testimony based beliefs are on-balance immediately and defeasibly warranted. The rational deception objection says that ambitious presumptivism is not true because it is sometimes rational for a speaker to assert lies rather than truths. One logically possible reply is to argue that it is never rational for a speaker to assert lies rather than truths. In this essay, I develop such a non-conciliatory response to the rational deception objection.

In chapter 1, I explain ambitious presumptivism and the rational deception objection. I identify Kant's prohibition against lying as a historical predecessor to the non-conciliatory response to the rational deception objection. I then identify Burge as the heir apparent to a neo-Kantian non-conciliatory response to the rational deception objection. In chapter 2, I explain my interpretation of how Burge is heir apparent to a neo-Kantian non-conciliatory response. I call Burge's response the ``functional unity'' argument.

In chapter 3, I defend my attribution to Burge of the functional unity argument. In chapters 4 and 5, I defend the functional unity argument itself from the most influential objections raised against it. in chapter 6, I defend the functional unity argument from the classic murderer-at-the-door objection that dogged Kant's prohibition against lying.