This article examines a much cited but little understood aspect of the Latin American intellectual and cultural ferment of the 1910s and 1920s: the frequency with which intellectuals from the southeastern Brazilian state of São Paulo referred to developments in post Sáenz Peña Argentina, and to a lesser extent in Uruguay and Chile. In books, pamphlets, speeches, and the pages of a vibrant periodical press—all key sources for this article—São Paulo intellectuals extolled developments in the Southern Cone, holding them out for imitation, especially in their home state. News of such developments reached São Paulo through varied sources, including the writings of foreign travelers, which reached intellectuals and their publics through different means. Turning from circuits and sources to motives and meanings, the Argentine allusion conveyed aspects of how these intellectuals were thinking about their own society. The sense that São Paulo, in particular, might be “ready” for reform tending toward democratization, as had taken place in Argentina, Uruguay, and Chile, was accompanied by a belief in the difference of their southeastern state from other Brazilian states and its affinities with climactically temperate and racially “white” Spanish America. While these imagined affinities were soon forgotten, that sense of difference—among other legacies of this crucial period—would remain.