To a large extent, recent debates on conspiracy theories have been based on what we call the “doxastic assumption”. According to that assumption, a person who supports a conspiracy theory believes that the theory is (likely to be) true, or at least equally plausible as the “official explanation”. In this paper we argue that the doxastic assumption does not always hold. There are, indeed, “non-doxastic conspiracy theories”: theories that have many supporters who do not really believe in their truth or likelihood. One implication of this view is that some debunking strategies that have been suggested to fight conspiracy theories are doomed to fail, since they are based on the false view that supporting a conspiracy theory means, ipso facto, believing in it.