At the MPIWG I plan to pursue a project that has its origins in the memorable workshop Moral Authority of Nature at the Institute in 1999–2000. My current focus is on the semantic range and conceptual status of phusis ("nature") and related lexical terms in fifth-century BCE Greek literature; in particular, I am interested in tracing the development of the use of phusis as designating “species nature” (in an anthropological or scientific sense, for example in Herodotus 3.80.4 or the Hippocratic corpus, passim) to its use in Athenian tragedy, where it appears in claims about ethical or moral behavior (for example, Sophocles' Antigone 523: "It's not my nature to join in hatred, but to join in love"). This inquiry, which brings me to the border of several disciplines, including the history of science, aims to contribute to our understanding of the nomos/phusis debate animating the teachings of the early sophists, though my focus will be primarily on the rhetoric and ideologics of phusis in tragedy—with implications for contemporary thinking about "nature," the "given," the contingent, the essential.