I criticise Cass Sunstein and Adrian Vermeule’s influential critique of conspiracy theories in “Conspiracy Theories: Causes and Cures”. I argue that their position depends on an equivocation over the meaning of the term ‘conspiracy theory’. This equivocation reflects a widespread assumption that conspiracy theories tend to be false, unjustified and harmful, and that, as a result, we can speak as if all conspiracy theories are objectionable in each of these three ways. I argue that this assumption is itself false, unjustified, and harmful. There are many true, justified, and/or beneficial conspiracy theories. This is because people often conspire, we often have good reason to believe that people are conspiring, and there is often a significa...