I provide a critical appreciation of the considerable legacies of Ostrom and Hardin to the literature on the commons. First, how valid is Ostrom’s critique of Hardin’s tragedy of the commons? Second, how generalizable is Ostrom’s institutional design principles for long-lived commons? Finally, how justified is Ostrom’s critique of privatization, markets and the Leviathan solutions to the tragedy of the commons? Following a reassessment of the evidence and reinterpretation of Ostrom’s (1990) book and supplemented by field work, my preliminary findings suggest that, first, her critique of Hardin is valid in the special case of small-scale, locally governed commons while Hardin seem justified for large scale, national, regional and global commons. Second, studies (i.e. Cox et al, 2010) arguing for the generalizability of Ostrom’s institutional design principles have methodological issues and more rigorous studies are needed. Finally, Ostrom is justified for her critique of the Leviathan solution to the tragedy of commons but a rethinking is needed of her critique of private property rights and markets. I conclude by acknowledging a debt of gratitude to Ostrom for laying the foundations for the third generation research agenda on the commons and inspiring a new generation of scholars.