This article analyses how the metapsychology of psychoanalytic listening proposed by Daniel Widlöcher led to the concept of co-thinking, which concerns the mechanisms that shape co-associativity in the session. More than the content, co-thinking targets the transmission of the associative process itself. The article traces the fundamental components of this process. It highlights the value of intentional action that the act of speaking acquires, thanks to interpretation, in the service of hallucinatory wish-fulfilment. The article emphasizes the passivity of both the analyst and the analysand that characterizes the early stages, leading to inferential work based on free-floating attention. The place of the body that emerges in co-thinking and the function of a form of second co-thinking in the transmission of psychoanalysis are then examined. Particular attention is paid to the links between transference and co-thinking, with a clinical fragment illustrating their close connection.