Socio-cultural psychologists have studied many social practices that are relevant to learning and development. In these practices, the other is significant: he or she cares before guiding, he or she shares something that fuels productive interaction. The notion of intersubjectivity was elaborated to account for maintenance of communication in practices that lead to development and learning. The social practices of synchronous (electronic) discussions are newcomers that seem strange to educators or psychologists: People seat alone by their computers and interact with others they don’t see and often don’t know. The interactions are often lopsided, interrupted and rudimentary. Yet, sometimes, people seem to learn in or from these strange interactions. How can such learning occur? Is it possible to discern any kind of intersubjectivity in synchronous discussions? We approach these questions in this paper. A necessary step in this enterprise is to come back to the origins of intersubjectivity and to the different senses it has received to account for maintenance of communication.