Whereas science is fundamentally a result of a dialogic debate, the authoritative approach has been conceived of as a fundamental part of school science. Dialogic interactions encompass the mutual appreciation of different ideas manifested in teacher supportiveness toward students and, in authoritative interactions, the focus is more on the science's or teacher's point of view. Whereas dialogic and authoritative interactions have been viewed as oppositional in recent educational research, authoritative interactions could well be the seed for and give strength and meaning to dialogic interactions, and thus, to the overall dialogue. The focus in this study is on the interplay between authoritative and dialogic interactions rather than on the rivalry between them. In other words, we present how both dialogic and authoritative interactions can be essential for teacher orchestration of whole-class discussions. This is achieved through a temporal consideration of the interactions and an in-depth analysis of selected episodes of a case science teacher. Interpretations are complemented with teacher reflections to shed light on the on-the-fly decisions made by the teacher when orchestrating dialogue. Implications for educational research and teacher education are discussed.