A substantial amount of philosophical work has been done on what ignorance is-is it simply the lack of a true belief? Or is ignorance the absence of knowledge? (see Peels 2010). There has been even more philosophical work on the ethics of acting out of ignorance-can ignorance excuse taking an action that has bad consequences? And, if so, under what circumstances can it provide such an excuse? (see Peels 2014). But as Robert Proctor suggests, there has not been much philosophical work on what it is to make someone ignorant. (The term ‘making someone ignorant’ might suggest that this per­ son was not ignorant beforehand. However, following Proctor, I also mean to include cases where someone acts to simply maintain someone else in a state of ignorance that she is already in. In other words, I use the term ‘making someone ignorant’ here to refer to cases that might also be described as cases of simply ‘keeping someone ignorant.’)One way to make someone ignorant about a particular topic is to inten­ tionally cause her to have a false belief. In other words, you might deceive her. For instance, Director of National Intelligence James Clapper lied to Congress (“Does the NSA collect any type of data at all on millions, or hun­ dreds of millions, of Americans?” “No sir.”) in order to keep us ignorant about the extent to which our personal communications are under govern­ ment surveillance (see Fallis 2015a, p.335). Clapper intended to put us into a state of what Rik Peels (2014, p.485) calls disbelieving ignorance. That is, he intended to make us ignorant of one thing by getting us to believe the opposite.