Speculative Epistemologies is about truth effects in sf, which stands for both science fiction and speculative fiction. It examines six narratives, one from each decade from the 1960s to the 2010s, that challenge dominant assumptions about the normal, the possible, and the real. It asks what the patterns of overlap and interference generated by texts located in border territories that make their identification as sf problematic, and sometimes controversial, can reveal about the dynamics of sf's multiple subcultures (e.g. professionals, academics, and fans); the complexity of the genre's communities of practice and their routes of production, distribution, and reception; and the genre's shifting position within a broadly conceived field of literary and cultural production. The "speculative epistemologies" in these stories are counter-hegemonic ways of knowing, ways of imagining knowing differently, and the focus of this study is their effect on the formation of identities and communities. Combining the methods of genre theory, reception theory, and the sociology of cultural production, the readings of these six narratives trace a history of sf's increasingly feminist, racially and ethnically diverse, philosophically ambitious, and politically engaged character from the 1960s to the present.