At the end of the twentieth century, there was a trend in Chinese literature towards characterizing Chinese culture as the “unity of Tian (Heaven) and humanity 天人合一.” Rather than arguing against such a view, I present in this paper a series of debates over the paradoxes within the concept of unity as well as various notions of love, hoping to demonstrate the depth and complexity of this seemingly simple and dogmatic dictum so that those who cite it can be alert to its potential intricacies. I will discuss three elements which threaten to render the pursuit of oneness an impossible project: (1) the relation between naming and the named, which makes any conceptual attempt to attain oneness an infinite regress, as can be seen in Zhuangzi’s 莊子 argument against Hui Shi’s 惠施 oneness; (2) the gap between contemplation and practice, as can be seen in the contrast between Zhang Zai’s 張載 contemplative oneness and Cheng Hao’s 程顥 perceptual oneness; and (3) the self-bifurcating attentive acts of the heart-mind, which render any conscious endeavor to attain oneness a self-defeating project. Unlike Cheng Hao’s emphasis on the subjective experience of perceptual oneness, his followers posit its underlying metaphysical substance as qi or xing (nature) and believe that moral self-cultivation should start from a metaphysical insight into this substance. Zhu Xi 朱熹 rejects the approach of grounding ethics on metaphysics and argues that love is not based on the notion of unity in terms of qi. He sees the ultimate comprehension of unity rather as a “metaphysical promise,” a goal to be attained by following the Confucian Way of selfcultivation, which starts simply from reflection and practice on things near at hand.