This article presents the contrasting views and theories formulated by European intellectuals such as Claude Lévis-Strauss and Max Bense on the situation of Brazil and Latin America in relation to the main centers of twentieth century criticism. It analyzes improvisation as a fundamental reflection index on the possibilities that third world countries have for negotiating the European Cartesian paradigm. If for some thinkers improvisation and its corollaries are proof that these countries and their people would live forever on the margins or in negative dialectics within the heritage of Enlightenment reason, for others it is precisely there--in the possibility of reinventing reason from hybridisms, strategic appropriations, and re-readings--that the creative and autonomous potentials in the post-colonial world lie. This article is situated precisely in the conflict between reason and the tropics, and looks to bring the debate up to date.