1 Property, the Environment, and the Lockean Proviso Bas van der Vossen Forthcoming in Economics & Philosophy Appropriation puts to private use natural resources that would otherwise remain available and untouched, reducing (among other things) what was previously part of the environment. When natural resources are appropriated, in other words, they are removed from what’s available in common. Private ownership transforms what could or should remain shared and natural into what is private and economically valued. Environmental conservation, therefore, requires limiting or even rolling back private ownership of natural resources as a way to ensure that a healthy environment remains intact. Private property may or may not be justifiable as an institution, but if it is to be justifiable, its reach must be limited to protect the environment. So goes a common and popular understanding of the relation between property rights and the environment. (de Shalit 2000: 92; Meyer 2009; Eckersley 1992, 2001 and many others. A good overview of the literature on this point, containing many more references, is Liebell 2011.) And, at first sight at least, it has some plausibility. Market societies put natural resources to productive use, and thus encourage the exploitation of the natural world. The constant drive to put resources to productive use seems bound to create, and of course has created, serious environmental problems. Viewed in this manner, a clear opposition seems to hold between two different kinds of values. On the one hand, there are the values served by private property rights. These are primarily private and productive in nature – the values celebrated by friends of market society,