The year 2019 marks the hundredth anniversary of the May Fourth Movement. In order to reconsider the meaning and heuristic value of this movement in modern Chinese history, since 2017 the Institute of Modern History, Academia Sinica held a series of activities to commemorate it. This book is the result of a conference held in May 2018. The May Fourth Movement has long been regarded as a turning point in politics, literature, thought, art, and daily life in modern China. This book focuses on May Fourth intellectuals’ discussion of culture and politics, as well as the later “memorial politics,” to investigate the crucial role of the May Fourth Movement in modern Chinese history. The historical figures discussed in the book include Yan Fu, Lin Shu, Liang Qichao, Chen Duxiu, Li Dazhao, Hu Shi, Fu Sinian, Qian Mu, Du Yaquan, Zhang Dongsun, and Shi Cuntong. The articles in the book study the content of their thought and the interactions among them to investigate the contradictions, conflicts, and mutual influences between the new and the old, and finally how May Fourth intellectuals established a new era centering on nationalism and searching for “democracy and science.” At the same time, some of these intellectuals started to reflect on the limitations of democracy, science, and patriotism. The intellectual movement of the May Fourth period marks the beginning of modern China, and the ideals put forward in it still remain unfinished goals to be fulfilled in the future.