John Krutilla, an economist at Resources for the Future, wanted economics to overcome the impasse left behind by the schism between Gifford Pinchots conservationism of resources for human ends and John Muirs preservation of the environment for its own sake. In the 1960s, even as Krutilla was working on these issues, economics was redefining itself from the study of material welfare to the study of opportunity costs and tradeoffs. Making use of this redefinition, Krutilla pushed economics to the point that it could embrace Muirs vision as well as Pinchots. He argued that if humans preferred a preserved state to a developed one, then such preferences were every bit as economic as development. Either way, there were opportunity costs and an economic choice to be made.