The question of the relation between the collective and the individual has had a long but patchy history within both philosophy and psychology. In this chapter we consider some arguments that could be adopted for the primacy of the we, and examine their conceptual and empirical implications. We argue that the we needs to be seen as a developing and dynamic identity, not as something that exists fully fledged from the start. The concept of we thus needs more nuanced and differentiated treatment than currently exists, distinguishing it from the idea of a ‘common ground’ and discerning multiple senses of ‘we-ness’. At an empirical level, beginning from the shared history of human evolution and prenatal existence, a simple sense of pre-reflective we-ness, we argue, emerges from second-person I-you engagement in earliest infancy. Developmentally, experientially and conceptually, engagement remains fundamental to the we throughout its many forms, characterized by reciprocal interaction and conditioned by the normative aspects of mutual addressing.