This paper interprets the Enlightenment spirit in Carsun Chang's neo-Confucianism from a modern vs. postmodern perspective, and further, to explore his approach for the issue of the criticisms of modernity. I point out that the problem of so-called "hegemony of reason" results from the employment of instrumental reason, which originates from positivism prevailing in modern age, and consequentially tends to the unavoidable phenomenon of cultural bias and social domination. For the elimination of the deficiencies of modernity, Habermas and Lyotard adopt the different approaches respectively: the former makes an effort to the completion of unfinished project of Enlightenment, and the latter focuses on the deconstruction of modernity. From this point of view, I indicate that just as Habermas, there is also an unfinished project of neo-Confucianism for Chang. Instead of Lyotard's approach of deconstruction, Chang's approach to remedy the deficiencies of modernity is the Enlightenment project of neo-Confucianism which based on both ren and zhi. That is to say, for Chang and Habermas, the solution of the deficiencies of modernity should be still based on human reason, and at this point, we could seek the philosophical resources from both Western Enlightenment tradition and Chinese neo-Confucianism to response the related challenges in postmodern era.