This paper uses concepts from infant research to describe the therapeutic action of psychoanalysis. Louis Sander's model of bidirectional mutual influence implies that agency is a property of all living things. Studying sleep-wake cycles, Sander concludes that these are mutually regulated; the infant uses his state to guide his pole of the bidirectionality. It is in the “moment of meeting,” when the caregiving surround acknowledges the infant state in a way that “fits,” lies the beginnings of the infant's sense of agency. I suggest that one can make links between how a sense of agency develops in infancy and how this concept can be used in psychoanalytic treatment. Specifically, a bidirectional stance, a continuous attention to affect and state, and a systematic inquiry into how the patient is experiencing the analytic activity foster a sense of agency. Clinical examples illustrate the thesis.