This essay examines the Brazilian deforestation debate to explicate the beginnings of a post-modern theory of argumentation. Modernist argumentation reflects two distinct approaches, found in the deforestation controversy. The first approach, ‘universal minimilization,’ presumes that the survival of humanity is sufficient grounds upon which to base argument. The alternative, ‘strategic manipulation,’ results in argument being employed as a technical device to advance one's interest. In place of the modernist approach, we offer an ecocentric theory of argumentation. This conception calls for (...) individuals to set aside differences in values to sustain humanity but at the same time to be sensitive to differences in costs and benefits that accrue from common efforts to persons differently situated. Additionally, this view operates with a tacit working assumption that environmental questions are not discrete entities to be evaluated separately. Rather, people must act collectively on a range of interconnected issues to ensure survival. (shrink)