Abstract: Rationalization occupies a central place in Max Weber's thought. However, Weber's discussion of rationalization in the administrative sphere (i.e., the emergence of modern bureaucracy) is not as detailed and systematic as his analysis of rationalization in the economic sphere (i.e., the birth of capitalism). Specifically, Weber did not reveal the religious and ethical basis behind the emergency of rational bureaucracy as he did with Calvinism behind the spirit of capitalism. In Weber's Economy and Society, the discussion of the administrative rationalization seems to make a "leap" of argument from the economic to the administrative sphere, which seems not particularly illuminating to our understanding of the complexity of the administrative rationalization, especially its underlying ethics. Therefore, in this paper we first return to the historical context in which Weber's theory of bureaucratization came into being, namely the Prussian bureaucracy from the seventeenth to nineteenth centuries. By looking into the historical process of rationalization in the Prussian administration, we explore the important role of Pietist ethics in the rise and fall of the spirit of the Prussian bureaucracy. The study offers an analysis of how Pietism shaped the Prussian bureaucracy through its religious doctrines of "emotion", "worldliness", and "authority". In so doing, the paper touches upon a topic that is not addressed by Weber in his theory of bureaucracy. Finally, we discuss the differences between the spirit of bureaucracy and the spirit of capitalism, and the possible interactions between the two processes, and propose the possibility of exploring the interplay between rationalization processes in different social domains for future research.

Key words: rationalization, bureaucratization, Pietism, Protestant ethics, Prussia