Human rights theory generally conceptualizes freedom of thought, conscience, religion, and belief as well as freedom of opinion and expression, as offering absolute protection in what is called the forum internum. At a minimum, this is taken to mean the right to maintain thoughts in one’s own mind, whatever they may be and independently of how others may feel about them. However, if we adopt this stance, it seems to imply that there exists an absolute right to hold psychotic delusions. (...) This article takes the position that this conclusion is ethically problematic from the perspective of psychiatric treatment and the rights of persons with psychosis. The article reflects on this particular challenge and sets forth an understanding of freedom in the forum internum that might apply to situations where for various reasons it is not, necessarily accurate to maintain that persons have an absolute right to their own thoughts. For the purpose of proposing such an understanding, the article engages with current debates within human rights theory and political philosophy and analyzes discussions about psychotic delusions and the way in which involuntary treatment is justified. Based on this analysis, this article in turn conceptualizes freedom in the forum internum as ‘negative liberty’, ‘authenticity’, and ‘capability’. This article suggests that when forum internum is redefined as encompassing a right to certain internal capabilities, the right remains meaningful for persons with psychotic delusions as well. (shrink)