All contemporary psychoanalytic schools formally address, and in their day-to-day clinical work all practicing clinicians consider, the interactive aspects of analytic process. However, as I indicated in Chapter 3, how “interaction” is defi ned is another matter. In this chapter I would like to further explicate the concept of interpsychic interaction – the unconscious and preconscious transference-countertransference processes that underlie the enacted dimension of analytic process. I will distinguish interpsychic interaction from interpersonal interaction and from the concept and theory of intersubjectivity, and discuss how it relates to the analytic third. Following this theoretical grounding, I will take up the idea of co-creation, or co-construction, a term widely employed in contemporary discourse, and how it relates to what transpires in the enacted dimension. Does characterizing enactment as “co-created” or “co-constructed” clarify or obscure the nature of the unconscious, dynamic process involved? What exactly is it that is co-created?