Despite a span of thirty-seven years stretching the dates of their publication, Lessing’s The Marriages between Zones Three, Four, and Five (1980) and The Cleft (2007) share a common theme and genre (space fiction). Set in an unspecified past in imaginary universes, they both chronicle how two geographically separate and culturally divergent communities join forces in a collective struggle to subvert the effects of an inscrutable power enveloping their respective lands. This paper argues that, through their foregrounding of utopian longing, The Marriages and The Cleft present a coherent vision of humanity and thus can be seen as instruments to “cultivate humanity” (Nussbaum 1997). Employing the cognitive tools of schemas and scripts (Schank and Abelson 1977), the paper explores the ways Lessing enforces her social project and, simultaneously, attempts to modify the reader’s cognitive schema of humanity through cognitive scripting. It arrives at two main conclusions. First, Lessing’s five-component humanity script not only closely corresponds to M. Scott Peck’s (1987) well-established model of community building, but it outweighs the latter in its scope. Second, in her formulation of the concept of ideal society, Lessing, rather than resorting to radical approaches and ideologies, opts for “reforming society in movement and change” (Greene 1994: 188).