This book traces the issue in argumentative discussions from its emergence to its evolution. The book makes use of naturally occurred data of spoken argumentation to investigate how an issue is raised and possibly negotiated in argumentative discussions between young children (aged 2 to 6 years) and adults. The author proposes a typology of the emergence of issues based on the argumentative agency of the interlocutors. Moreover, the investigation sheds light on how issues evolve through negotiation among the involved interlocutors and how issues may be related to the interlocutors' endoxa. By applying an interdisciplinary approach including argumentation theory (the pragma-dialectical model of a critical discussion and the Argumentum Model of Topics) as well as sociocultural developmental psychology this work allows for a careful consideration of the many aspects that come into play when young children start or engage in an argumentative discussions with adults.