The unity of nature as a theme in Eriugena’s De diuina praedestinatione has been acknowledged. This essay contrasts it with the idea of nature assumed, adopted or advanced by other disputants in the ninth-century predestination debate. It begins from the fundamental Augustinian anthropology distinguishing the will (uelle) and the ability (posse) to sin. Hincmar of Reims and Lupus of Ferrières offered opposing perspectives on this analysis. Eriugena presented an altogether different configuration of the same elements and makes the human will an important source of continuity between prelapsarian and fallen humanity. The question of what kind of nature was lost at the fall recurred throughout the debate and raised problems of language and metaphor in Carolingian theology. The disputants offer a kind of sliding scale interposing nature at different points between God and humanity. Whereas most of the disputants accepted this stratified model for its capacity to accommodate a moral tropology, Eriugena collapses it : nature cannot be separated from God, nor humanity from nature. Throughout the works, there are explicit binaries of a traditional mold, like natura and gratia, and binaries that may be inferred, like Florus’s natura peccatrix versus Eriugena’s natura creatrix, that give shape to these contrasting models. In the end, Eriugena’s implicit assimilation of God and nature stands dramatically against Gottschalk of Orbais’s more or less explicit identification of God and grace.