Making Up Sex: Life beyond Hacking’s Distinction between Human and Natural Kinds

Sex is a particularly fitting object for historical ontology. Historians of biology have shown how sexually differentiated bodies are represented through the interplay of knowledge, power, and ethics. Yet recent research in the biology of sex suggests that naming sex has even deeper ontological consequences than Hacking envisioned. This chapter brings feminist metaphysics and new materialism into dialogue with contemporary philosophy of biology to argue that Hacking’s distinction between interactive (human) and indifferent (natural) kinds cannot be sustained in the case of sex. Drawing on enactivist and externalist accounts of representation, I argue that responsiveness to classification is not confined to beings capable of conceptual self-understanding but extends to organisms whose agential, perceptual, and niche-constructing capacities make them representers in a broader sense. Drawing on developmental biology and feminist science studies, I further argue that sexed bodies are plastic in ways that allow social classifications to materially transform their morphology, physiology, and behavior, and that this plasticity is selective and character-specific rather than uniform. Finally, drawing on extended inheritance and niche construction, I argue that sexed bodies are historical entities that retain epigenetic and developmental traces of past interactions across both ontogenetic and phylogenetic timescales. The boundary between Hacking’s natural and human kinds thus blurs not by attributing agency or discursivity to matter in general, as new materialists propose, but by attending to the distinctive relational, plastic, and historical ontology of organismal matter.