The study explores the complex relationship between various manifestations of the self and the other in twentieth century Science Fiction (SF). According to Richard Bernstein (1983), much modem thought is still influenced by Cartesian Anxiety, a deeply-rooted tendency to polarise or dichotomise arguments and living entities, demarcating one side as positive, necessary and desirable and the other as negative and destructive. Various embodiments of the self and the other are polarised in such a manner in both literature and life and this results in an impoverishment as the parties involved never really engage in dialogue, understand or learn from one another. Because it features a variety of truly alien creatures, SF literature has been chosen as the genre within which the concept of otherness will be discussed. Moreover, as an innovative and subversive genre, SF approaches old issues from a new perspective. It is believed that SF can shed new light on the old dichotomy of the self and the other. The study includes randomly and personally chosen works by authors such as Wells, Wyndham, Butler, Le Guin, Card and Tepper. The tendency to demarcate women, alien offspring and alien life forms in general as the other is discussed in separate chapters, with the focus on why given selves and society feel compelled to marginalise and destroy otherness. Various theories as to what the fear of the other represents are laid out and the Jungian interpretation that fear of the other is linked to anxiety about expressing what Jung calls the psyche's shadow side is suggested. Hermeneutic principles, particularly the theories of H-G Gadamer, are then used to provide a model of a fruitful discourse between a self and other where the decentered self engages in an equal and open-ended dialogue with the other, resulting in greater understanding and acceptance as both parties learn from one another and incorporate that new understanding into their sense of self-identity and humanity.