Two trends of Confucianism exist in postwar Taiwan: one official version represented by textbooks in primary and middle schools; another popular version embraced by scholars and the intelligentsia. The latter version manifests the identity of popular culture in Taiwan; the former official version is a powerful booster of national aspirations. These two trends strongly remind us of the two familiar Confucian traditions-the great and the small-that have flourished throughout the intellectual history of China. This essay explores the significance of these two traditions in contemporary Taiwan for her open future in the 21st century. I will treat four themes: 1.What tensions and differences in philosophical contents, as well as in sociopolitical repercussions, there are between these two traditions in Taiwan; 2.How these two pairs of two versions of Confucianism differ-the historical pair of the great and the small traditions in China, the contemporary pair of the offical and the popular Traditions in Taiwan; 3.What light such differences throws on classical Confucianism; 4. What contemporary significance such a comparison has for contemporary Taiwan. I will explore the above themes from two futuristic angles: interactive harmony between the social and the subjective, and interactive harmony between the human and the ecological. This is to follow Confucius' injunction to warm up the old to know the new," i.e., to prepare us for21st-century Taiwan.