Having passed through the tumultuous twentieth century, in which our very existence came under severe threat, mankind is still faced with a host of challenges. Numerous possibilities present themselves as well. How to address these challenges and seize these possibilities is the concern of contemporary Chinese philosophy, which has to address these issues not only because of the historical experiences of the Chinese people but also because of the need to adjust traditional values. In this respect, Tang Jun-yi (1909-1978) is representative both of Chinese philosophical contexts and of contemporary Confucian currents, for he provides profound reflections on the possibility of a perpetual peace. This paper treats Tang's thoughts on perpetual peace in three parts. In the first part, I state briefly the context in which Tang mentions the idea of peace. The second part compares and contrasts Tang's views on peace with those expressed in Kant's On Perpetual Peace. In the third part, I consider how Tang's religious viewpoint contrasts with that of Kant, and how it renders a response to and a critique of modernity in giving a cultural orientation. Through these considerations in three parts, I would like to ponder on the space left open by Tang's acute observation of cultural difference. Although Tang, unlike Kant, underestimates the importance of rights in peace, his religious turn pays attention to the public nature of culture, and as such it is in line with Kant's views. Tang's theory of peace touches on cosmopolitan universality and constitutes a meaningful dimension for thinking about contemporary Chinese philosophy and the critique of modernity; Tang's idea of the world of humanity qua public space can provide a clue to thinking about the possibility of human beings living together peacefully.