 A “radical” environmental philosophy challenges foundational assumptions and claims of canonical philosophy in the context of environmental issues. These challenges are “radical” in the etymological sense that they “go to the roots” of environmental problems—typically, the conceptual roots—and in the historical sense that they had never before been part of a moral theory. (This description permits that what was “radical” at one time may no longer be radical.) One of the most influential radical positions is “deep ecology”. 