  However, this objection to D1 (and D2, D3, and D4) is not necessarily compelling. It may be argued that negative deception is not deception at all. After all, no false belief has been acquired or sustained. It may be argued that to prevent someone from acquiring a true belief is to keep that person in ignorance, or to keep that person “in the dark,” rather than to deceive that person (Mahon 2007, 187–188; cf. Carson 2010, 53). The state of being ignorant is not the same as the state of being mistaken. One may not know what city is the capital city of Estonia (Tallinn); this is different from mistakenly believing that Riga is the capital city of Estonia. Similarly, although it is more unusual, rendering a person ignorant of some matter is not the same as deceiving that person, at least if it results in no false belief. For example, in the 2004 science-fiction film The Eternal Sunshine of the Spotless Mind, people go to Lacuna, Inc., to have their memories of their previous relationships, as well as their visits, erased. Those who run Lacuna, Inc., make their clients forget things, or render them ignorant of things. They do not deceive them in doing this. Chisholm and Feehan admit that Augustine and Aquinas “do not call it ‘deception’” to “hide the truth” (Chisholm and Feehan 1977, 187).