This work presents a novel theoretical concept of the therapeutic action which reworks and integrates modern theories, derived from systems theory and cybernetics, emerging with wide-ranging reflections also for teaching and research. The authors conceive of the therapeutic action as a result of a match or process in which therapists and patients participate together. The experience of the therapist plays a central role in shaping the theory and opens a perspective that helps bridge the gap, often lamented, between research and practice.