ABSTRACT
Philosophers have always been interested in conspiracies, but the philosophical debate on conspiracy theories is a pretty recent phenomenon. Karl Popper (1950) wrote about the ‘conspiracy theory of society’, but his discussion concerned issues of intentional explanations in general rather than conspiracy theories proper. In this chapter, we will review the philosophical debate and distinguish between four questions that philosophers have considered. The questions we have in mind are (1) the conceptual question of what the appropriate definition of the term ‘conspiracy theory’ is; (2) the epistemic question about the rationality and justification of conspiratorial beliefs; (3) the moral question of the ethical status of conspiracy theorising; and (4) the practical question of how decision-makers should deal with conspiracy theories. Obviously, the questions are closely connected to one another. Whether conspiracy theories are, generally speaking, plausible or implausible explanations depends on what is meant by the concept. The ethical status of conspiracy theorising in turn depends partly on the plausibility of conspiracy theories. Finally, whether we should fight against the spreading of conspiracy theories surely depends, at least to some extent, on the ethical status of the theories. Therefore, by defining the key concept suitably, one can try to settle most of the questions in the debate – not an unusual situation in philosophy.
