This paper focuses on the later thought of Justus Möser (1720-1794) and its meaning in the social context of the eighteenth century. Through our investigation, we discover a practical intention in his thought and unearth his original position in the modern German history of ideas. Generally, though especially in Japan, the modern German history of ideas is a genealogy of renowned philosophers, including Kant, Fichte, and Hegel; few places are reserved for Möser. However, the modern German history of ideas is far more complex than the history of philosophy allows, because it developed during social upheaval, particularly the French Revolution. Discussions concerning theory and practice show the relation between societal trends and thought. Kant's paper was the epicenter of such discussions in the late eighteenth century, drawing responses from many thinkers, including Möser, who wrote his theory and practice from a critical viewpoint of Kant's theoretical and abstract argument. We clarify Möser's concrete logic in his historicism, which is based on facts from society and history, and contrast it with Kant's argument. Beyond traditional evaluations of Möser as a conservative or a political romanticist, this paper portrays him as an Enlightenment thinker for society.