[Change, transformation, evolution].

"Change", "transformation" and "evolution" are terms not at all interchangeable. They point at realities and deeply apply to mechanisms which partially intertwine each other without ever being overlapped or confused. We would like to distinguish and investigate their diffusion in former and current psychological approaches, especially when dealing with the analysis and follow-up of a moving process. We will present some illustrations, in the field of the phenomeno-structural method, which, after having dedicated an important part of its works to the enlightment of the organization of the mental structure, from 1920 to 1950, felt the need, from the 50's onwards, to follow its evolution through a set of psychological modifications pointing in a main direction: during normal and pathological development throughout childhood or at the critical moment of the adolescence period, in psychosurgery or psychobiological practices, then in cases of appearing and disappearing of delusional processes, in the follow-up of determining transformation phases during alcoholic detoxification, or, more recently, in the appreciation of the psychotherapeutic practices (directed daydream, relaxation). We will show how this perspective, standing apart and suspicious to the restrictive current tendency towards evaluation, takes part in a much wider theoretical and methodological frame with a constant concern to consider the sustainable effects and the limits of various events, circumstances or procedures on the structure of personality, through a vast and coherent understanding of the underlying psychological mechanisms which steer them by giving them sense.