"Quassim Cassam has done the world a great service. This short, bracing and easily accessible book is not only a compelling read - it is also a much-needed weapon in the war against lies and the battle for truth. Methodically, he takes apart the mindset of the conspiracy theorist and shows why such theories arise, why they appeal and why they cause real damage. Truth has taken a battering in recent years. Now, thanks to Cassam, the truth is hitting back."Jonathan Freedland"Those who engage in [conspiracy theory]... need to protect themselves against its corrupting effects. The philosopher Quassim Cassam is, I think, our wisest writer on this matter. I’d heartily recommend his work..."Matthew Sweet, BBC Radio Presenter"Interesting and informative" Quest Magazine"Beautifully clear, thoroughly researched, rigorous and wide-ranging."Society