The variety of accounts of theory of mind development, arising from distinct theoretical perspectives, have focused on children's causal-explanatory views on the mind and have not developed accounts of children's normative judgments of the mental domain. This review maintains that such a focus is unfortunate and leaves our understanding of belief as a concept incomplete. First, by presenting an alternative framework that treats belief as a normative concept, this account discusses the central importance of children's understanding of epistemic justification and their appreciation of the normative significance of others' reasons for belief. Next, this review of the relevant theory of mind literature proposes a new way of thinking about the findings of various domains in this field and gives particular attention to prior work on false belief, origins or sources of belief, and the distinctions between fantastical and epistemic states. On the basis of this review, it is concluded that in order to accurately assess the development of the concept of belief, further research is required on children's views of how beliefs ought to be formed, their evaluation of justified and unjustified believers, and the notions of duty or responsibility they associate with epistemic agents.