Johann Georg Hamann, a contemporary of Kant and Herder, was an important German philosopher of the 18th century, whose significance, however, is not sufficiently recognized today. His cryptic and short writings full of allusions and deep scholarship do not make him an easily accessible writer. He was a sharp critic of sophistry maskerading as philosophy, thus taking over the role of Socrates for his time, connecting a defense of Christian beliefs with a radical re-interpretation of enlightenment, thereby trying to enlighten enlightenment about itself. Hamann's concept of reason as language is an important contribution to the understanding of human nature as such, stressing the concreteness and historicality of human reason. Contrary to earlier interpretations, though, Hamann is no irrationalist, but a thinker who ridicules the absurdities of enlightenment rationalism and proved to be an important source of inspiration for writers like Sören Kierkegaard and Ernst Jünger.