This chapter starts with an outline of the notion of ignorance we will employ, ignorance as absence of knowledge. The authors distinguish two elements that figure in most ignorance ascriptions: a generic ascription of ignorance and a more precise description of the attitudes a cognizer holds in a given instance of ignorance. Ordinary ways of speaking about ignorance can refer to the absence of a range of cognitive achievements. They pull away from the idea that ignorance is standardly or primarily the absence of propositional knowledge. Preferred Ignorance can thus be blameworthy in similar ways that Presumed Knowledge is. Those who prefer not to know can seem to dismiss domains of knowledge that to others appear valuable or even urgent. This kind of ignorance is widespread with respect to trivia, but also with respect to any number of facts that simply do not figure in a particular person’s life.