"The Chinese people, too, went through all kinds of vicissitudes in their religious development"

Hu Shih is referring to the history of religion in China, which has experienced numerous changes and obstacles with time. The word "vicissitudes" recommends that this advancement was not smooth or simple, but rather was marked by ups and downs, twists and turns. This might include durations of religious fervor and orthodoxy, along with times of dispute, repression, or adaptation in action to altering social, political, or cultural forces. In General, Hu Shih is acknowledging the complexity and diversity of religious practices and beliefs in China, and recognizing the significance of understanding this history in shaping Chinese culture and society.