The “Common Heritage of Humanity” is an idea that took on a legal form beginning in the 1960s. It is based on four founding elements: resources classified as “CHH” are the property of no one; they must be shared equitably; exploited for peaceful aims; and are therefore managed by an international regulating mechanism. Applied to international ocean seabeds, the legal concept of a Common Heritage of Humanity is a principle based on ideals of equity and peace among States. Drawn up at the U.N. in the context of international negotiations on the Law of the Sea, the concept was initially a product of issues linked to the extraction of minerals (manganese, cobalt, oil). Since the 2000s, it has sparked new political and diplomatic interest in a quite different domain, centering on the issue of medical patents involving marine biodiversity. Although it originally embodied the promise of a “new world order”, it now looks more like an “empty shell” or as if a moral judgment were now out of date in contemporary international relations. Following the itinerary of this principle in U.N. negotiations through these two moments and these two issues, this work examines the transformations in production practices of international norms since the 1960s and in what ways this change affects the agenda of environmental issues.