Bioethicists often draw sharp distinctions between hope and states like denial, self-deception, and unrealistic optimism. But what, exactly, is the difference between hope and its more suspect cousins? One common way of drawing the distinction focuses on accuracy of belief about the desired outcome: Hope, though perhaps sometimes misplaced, does not involve inaccuracy in the way that these other states do. Because inaccurate beliefs are thought to compromise informed decision making, bioethicists have considered these states to be ones where intervention (...) is needed either to correct the person’s mental state or to persuade the person to behave differently, or even to deny the person certain options. In this article, we argue that it is difficult to determine whether a patient is really in denial, self-deceived, or unrealistically optimistic. Moreover, even when we are confident that beliefs are unrealistic, they are not always as harmful as critics contend. As a result, we need to be more permissive in our approach to patients who we believe are unrealistically optimistic, in denial, or self-deceived—that is, unless patients significantly misunderstand their situation and thus make decisions that are clearly bad for them, we should not intervene by trying to change their mental states or persuade them to behave differently, or by paternalistically denying them certain options. (shrink)