Liang Qichao's novel The Future of New China views culture and commerce in international contexts under the rubric of datong. While the novel begins with a scene of cultural exchange and commerce, it soon centers on the foreign education and travel of two young protagonists, who are to become the founding fathers of a constitutional nation-state. The urgency of nation building plays out in the two young men's over the political, moral or populist means of achieving the nation. How does nation-state building relate to the initial datong cosmopolitanism? This paper suggests that Liang's nation contains international dimensions. The new Chinese nation is situated in a geopolitical network of nation-states, but it also aspires to self-determination and equality with other nations. The nation is to be built by resorting to a moral reform that contains the idea of tianxia (all under heaven). In his Discourse on the New Citizen, Liang calls for personal outlooks based on culture and morality rather than institutions or actual politics. The novel analyzes China's debates on reform and revolution; the present paper traces the connection between this moral quality of a nation and internationalism. I contend that Liang's nation-building projects an international type of aspiration toward tianxia.