Since the advent of neuroimaging technologies, their limits and possibilities have captivated scientists and philosophers. Thus far, the debate has largely concerned technical limits of our capacity to “read minds.” This paper extends the discussion concerning the limitations of neuroimaging to issues that are not dependent on technical issues or on our understanding of the complexity of brain activities. The author argues that there is a serious chance that brain scanning cannot replace usual intentional assertions, and that neuroimaging has principled limits. The information that people usually receive by neuroimaging is different in kind from the information they hear from what others tell them. To assert something is to act in a certain way, and scanners do not usually scan actions, but brain activities and the neural correlates of actions. Although it is possible to scan “mental assertions,” our usual assertions are not accompanied by separate “mental assertions.”
