In Republican China, new dictionaries promoted several aspects of the project to make Chinese culture compatible with science and to introduce democratic ideas. As inexpensive reference works, dictionaries also embodied the modernist principle that rational, secular knowledge could be made broadly available. As a result, new dictionaries both recorded and helped to define an emerging sense of Chinese national and scientific modernity during the May Fourth era. As part of the project of "scientization," they contributed to fundamental and wide-ranging cultural change. In addition, for the two largest publishers of Republican China, dictionaries proved to be popular and profitable titles that supplied vital revenue.