The authors propose that the process of psychic change involves the ‘working through’ of mourning for the loss of ‘theories of life’ that are based on narcissistic omnipotent beliefs. These theories need to be changed by other more realistic ones regarding how to resolve the inherent and natural problems of existence. Questioning the ‘truth’ of these theories of life, as well as the acquisition of the perception of the existence of time, makes up part of the process referred to, and this applies to the analyst in a certain way as much as to the patient. Such problems are lived, re-edited and revised in the transference/countertransfererce relationship. The authors present a clinical illustration. They explore the concepts of symmetry, asymmetry, homogenization and differentiation in Matte-Blanco's bi-logical theory and propose that these are important to the comprehension of the dynamic of the psychic changes which occur in a non-static analytic process.