Guy Fletcher, Dear Prudence (Oxford: Oxford University Press, 2021), pp. 1–223.

noteworthy contribution to the literature. Roy Sorensen’s ‘Lying to Mindless Machines’ offers a pioneering discussion of lying to mindless machines (AIs). Sorensen argues that we can lie to machines, but machines cannot lie to us. If he is right about the first claim, and we can lie to mindless machines, DECEPTION must be false: we need not intend to change someone’s mind (since machines have none) in order to lie. Most of the volume’s essays focus on how individual statements can be used to deliberately convey false propositions. Jennifer Saul’s article examines other ways in which falsehoods spread through communication. Sometimes falsehoods are produced by the aggregation of different discourses (Saul calls these aggregate falsehoods). For instance, a journal that disproportionately covers crimes by black people may create the false impression that black people aremore likely to commit crimes. Other times,media propagate falsehoods unintentionally, by mere negligence, because their journalists and editors did not check their sources as carefully as they should have (Saul calls these negligent falsehoods). Although aggregate and negligent falsehoods are not strictly speaking ‘lies’, they are common and can be immensely damaging to the communities that they target. To understand how nefarious stereotypes are created and spread, Saul concludes, researchers need to pay more attention to these neglected forms of disinformation. The volume is divided into four main sections, each dealing with one of the four topics mentioned in the title (lying, knowledge, ethics, politics). Due to space constraints, I have been unable to comment on the sections of knowledge and ethics, which indeed contain some excellent essays. If I have not discussed essays on politics, it is because (perhaps fittingly for a volume that deals with deception), none of the essays grouped under ‘politics’ discusses (or touches upon) the political implications of dishonest communication (with the exception of Saul’s essay). This may be the main weakness of the volume: despite being published in the ‘Engaged Philosophy’ series of Oxford University Press, it offers very little material that fits this label. That said, this is an important collection with several excellent contributions, some of which will contribute to redefining research in this field in the forthcoming years.