Inexpressible Ignorance

Sometimes, ignorance is inexpressible. Lewis recognized this when he argued, in “Ramseyan Humility,” that we cannot know which property occupies which causal role. This peculiar state of ignorance arises in a number of other domains too, including ignorance about our position in space and the identities of individuals. In these cases, one does not know something, and yet one cannot give voice to one's ignorance in a certain way. But what does the ignorance in these cases consist in? This essay argues that many standard models of ignorance cannot account for the phenomenon of inexpressible ignorance. It then develops an alternative model that does better, on which the ignorance consists in a failure to identify something by way of its nature or essence