ABSTRACT
In the theory and practice of person-centred therapy, it is held that an innate tendency within the client constitutes the sole agent for growth, `constructive personality change' (Rogers 1957: 96), achievement of potential and so on. This agent is called the actualising tendency. Of this tendency, Rogers (1951: 487) wrote that the human species `has one basic tendency and striving ± to actualize, maintain, and enhance the experiencing organism'. However, it is clear from Rogers' later writing (see, for example, Kirschenbaum and Henderson 1990a: 380) and (for example) the commentary of Barrett-Lennard (1998: 75) that the actualising tendency is not seen as a uniquely human characteristic but that it `is present generally in complex life forms'.
