In this chapter, I summarise the central theses defended in my monograph and explain how they fit together to provide us with a more complete picture of the nature and normative significance of agnosticism. I conclude that agnosticism is best conceived of as the mental state of questioning both the truth and falsity of some proposition, P – which can, but need not, be preceded by the mental act of refraining from judging P to be true or false – and is rationally appropriate whenever we take our evidence for and against P to be inconclusive.

In this chapter, I mount a sustained argument against Friedman’s claim that one is agnostic about whether P if and only if one is in an inquiring state of mind about whether P. I reject the claim that an inquiring state of mind entails agnosticism on the grounds that it fails to accommodate cases in which an agent inquires with the aim of ratcheting up an instance of (justified) believing to the status of knowledge or an instance of knowledge to the status of complete certainty. I reject the claim that agnosticism entails being in an inquiring state of mind on the grounds that it fails to accommodate cases in which a subject is agnostic towards P but are unmotivated to inquire about whether P because they believe or know that the question of whether P is unanswerable.

In this chapter, I apply the criteria vetted in Chapter 2 to the non-attitudinal accounts of Russell and Crawford, the metacognitive accounts of Masny and Raleigh, Wagner’s endorsed-indecision account, and Friedman’s question-directed attitude account. I demonstrate that each account fails to satisfy one or more of the criteria for a satisfactory descriptive account of agnosticism.