In this chapter, I advance a non-reductive, proposition-directed, sui generis account of agnosticism called the questioning-attitude account. The questioning-attitude account is non-reductive because it denies that agnosticism is reducible to other mental states like belief, desire, or intention. It is a proposition-directed account because it holds that the object of agnosticism is a proposition, as opposed to a question or another mental state. It is a sui generis account because it holds that unlike belief, which involves an affirming stance towards a proposition, or disbelief, which involves a denying stance towards a proposition, agnosticism involves a distinct questioning stance towards a proposition.

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 detail some of the main considerations that have led contemporary epistemologist to largely reject non-attitudinal accounts, which conceive of agnosticism chiefly in terms of a combined absence of belief and disbelief, in favour of views that see agnosticism as involving one or more attitudes. I conclude with a brief survey of the major contemporary attitudinal accounts of agnosticism.