  We propose a study of the constitution of meaning in human-computer
interaction based on Turing and Wittgenstein's definitions of thought,
understanding, and decision. We show by the comparative analysis of the
conceptual similarities and differences between the two authors that the common
sense between humans and machines is co-constituted in and from action and that
it is precisely in this co-constitution that lies the social value of their
interaction. This involves problematizing human-machine interaction around the
question of what it means to "follow a rule" to define and distinguish the
interpretative modes and decision-making behaviors of each. We conclude that
the mutualization of signs that takes place through the human-machine dialogue
is at the foundation of the constitution of a computerized society.
