Heidegger and hallucination

Can Heidegger account for hallucination? I argue that while Heidegger does not develop an account of hallucination, he gives us all the resources we need to develop such an account. I first discuss a prominent argument against the very possibility of such an account. I argue that this argument is mistaken. I then discuss Heidegger's brief remarks on hallucination. In analysing a particular case study, Heidegger claims that the subject hallucinates for two reasons. First, he fails to realize the distinction between the different ways entities are present to him. For this reason, he cannot encounter a particular entity as it is present. Second, he is unable to do anything about the fact and manner of the presence of that entity. He is ‘unable to move in his world freely’, as Heidegger puts it. I show how these remarks, when taken in combination with Heidegger's broader ontology, allow us to explain the possibility of hallucination in a distinctively Heideggerian way.