M R. X. Dentith

Conspiracy theories are often portrayed as unwarranted beliefs, typically supported by suspicious kinds of evidence. Yet contemporary work in Philosophy argues provisional belief in conspiracy theories is at the very least understandable---because conspiracies occur---and that if we take an evidential approach, judging individual conspiracy theories on their particular merits, belief in such theories turns out to be warranted in a range of cases. Drawing on this work, I examine the kinds of evidence typically associated with conspiracy theories, and show how the so-called evidential problems with conspiracy theories are also problems for the kinds of evidence put forward in support of other theories. As such, if there is a problem with the conspiracy theorist's use of evidence, it is one of principle: is the principle which guides the conspiracy theorist's use of evidence somehow in error? I argue that whatever we might think about conspiracy theories generally, there is no prima facie case for a scepticism of conspiracy theories based purely on their use of evidence.

Drawing on work by philosophers CAJ Coady and David Coady on the epistemology of rumours, I develop a theory which exploits the distinction between rumouring and rumour-mongering for the purpose of explaining why we should treat rumours as a species of justified belief. Whilst it is true that rumour-mongering, the act of passing on a rumour maliciously, presents a pathology of the normally reliable transmission of rumours, I will argue that rumours themselves have a generally reliable transmission process, that of rumouring, and should be considered to be examples of warranted beliefs. My argument will also touch on the association of rumours with another class of beliefs that are usually considered to be suspect, conspiracy theories. I will argue that whilst rumours are reliable (as a mechanism for the transmission of justified beliefs) the analysis of the transmission of conspiracy theories requires us to realise they are different to rumours in some important respects.

Conspiracy theories are typically thought to be examples of irrational beliefs, and thus unlikely to be warranted. However, recent work in Philosophy has challenged the claim that belief in conspiracy theories is irrational, showing that in a range of cases, belief in conspiracy theories is warranted. However, it is still often said that conspiracy theories are unlikely relative to non-conspiratorial explanations which account for the same phenomena. However, such arguments turn out to rest upon how we define what gets counted both as a ‘conspiracy’ and a ‘conspiracy theory’, and such arguments rest upon shaky assumptions. It turns out that it is not clear that conspiracy theories are prima facie unlikely, and so the claim that such theories do not typically appear in our accounts of the best explanations for particular kinds of events needs to be reevaluated.