This thesis examines challenges to Western Humanist constructions of the human in selected literature, specifically Angela Carter’s Nights at the Circus (1984), Marge Piercy’s Body of Glass (1991), and Michel Faber’s Under the Skin (2000). Interweaving cultural theory with literary analysis, this thesis explores and critiques constructions of the human through a Western Humanist perspective. Chapter One examines how Western Humanism has defined the human in opposition to the other through dominant dualisms, notably that of human/animal and human/machine. Within this chapter, it considers feminist and posthumanist critiques of Western Humanism, in order to speculate new forms of identity and subjectivity. Chapter Two is a literary analysis of the selected texts, arguing that the novels’ hybrid characters destabilise dominant dualisms underpinning Western Humanist constructions of the human. Inspired by Judith Butler’s gender performativity theory, Chapter Three explores performative identities of gender and humanness. In particular, it argues that humanness is a performative act rather than an innate state of identity, illustrated through a literary analysis of the selected texts.