The salience of the analyst's emotional engagement of the patient in fostering therapeutic change is reviewed and related to the theory of emotion implicitly or explicitly held by the analyst. The analyst's conceptualization of the analytic process, attribution of meaning to the analytic dialogue, selection of interventions, and recognition of the emotional component of treatment are explored as a function of the analyst's theory of emotion. A dynamic systems theory of emotion is proffered to illuminate the complex interactions that create the emotional experience of the patient and of the analyst and that affect the nature and quality of therapeutic process itself that have not been accounted for by the commonly held theories of emotion.