What is the point of restricting the ways that people acquire and share knowledge of one another’s minds, as people do in societies that hold ‘opacity doctrines’? Information about others’ intentions might not be necessary in those societies that can do without practices that rely on broadcasting them. But it is crucial to the way professional carers in Britain support people with intellectual disabilities who are often unable to communicate their needs and desires. Why, then, do experienced carers in one organisation make it harder for newcomers to learn what is going on inside these individuals’ minds? To understand this case we need to ask not only of the knowledge opacity negates, and of the social practices that it might disable, but also of the forms of ethical relationality and recognition that it might create. Doing so widens the opacity debate from a strictly cognitive one into a far-reaching investigation into the ways in which ethics and epistemology combine in our knowledge of one another.