This essay revisits one of the foundational settler texts of Canadian literature, Northrop Frye’s “Conclusion” to the Literary History of Canada. It offers a controversial re-reading of Northrop Frye’s infamous “garrison mentality” thesis from the perspective of contemporary eco-criticism, particularly in view of the global crisis of climate change. The essential ecological logic of Frye’s account is that human isolation from nature impedes humanity’s “fullest functioning as a species.” However, the logic of the garrison thesis has been implicitly shared by critics who purport to oppose Frye’s approach; at base, both Frye and his critics assume that human-nature interconnection fosters human potential and creativity. Drawing on a number of prominent environmental biologists and ecocritics, the essay demonstrates that the garrison mentality, in which humans maintain a respectful distance from nature, may be the most ecologically sound response. This opens up a provocative question: “What if the most crucial role for literature . . . is not to fuel and thrive on the individual quest for creative fulfillment and self-understanding, but to harness itself to the task of bringing human aspirations, collectively, within limits?”