We intend in this chapter to put forward a radical proposition about the relationship between language and the understanding of false beliefs. We begin by contrasting the roles that language acquisition might play with respect to the development of theory of mind reasoning, separating out the language-for-the-task from the social constructivist view of language as one of several facilitators of social cognition, and both of these from the strongest position that certain linguistic structures make available a representational format for false beliefs. We then present empirical data from a longitudinal study of normally developing preschool children and from our work with language-delayed oral deaf children, to test among the rival hypotheses for the role of language in the development of false belief reasoning. The empirical data make a suprisingly coherent story, though many pieces remain to be worked into the puzzle. The empirical story is at least suggestive enough that it forces us to examine the strongest theoretical position seriously, and ask, is it viable?