How does schizophrenia affect a subject's sense of self? In this paper, we discuss the experience of alienation of mental states and actions that can take place in schizophrenia. We begin by highlighting this experience in delusions of thought insertion and delusions of made feelings, impulses and actions. Next, we offer a proposal about the nature of this experience by utilizing some of the current philosophical research on self-knowledge. The proposal is that the experience of thoughts, feelings, impulses and actions as not being one's own is the experience of regarding those states as not being responsive to reasons. Then, we put forward a hypothesis about why schizophrenia can lead to this experience by drawing on the psychiatric literature on the disorder. The hypothesis is that subjects who suffer the four delusions are unable to regard some of their thoughts, feelings, impulses and actions as being responsive to reasons because they suffer from a tendency to focus their attention on their own perceptual experiences, as opposed to focusing it on the world. The lesson to draw from the alienation of mental states and actions caused by schizophrenia will be, finally, that two separate components normally make up our sense of self; two components that turn out to be dissociated in the four schizophrenic delusions discussed. These are, on the one hand, the self as the bearer, or host, of mental states and actions and, on the other hand, the self as the owner and agent, respectively, of those mental states and actions.