Tracing the History of a Super-Category: The 'Empirical' in German Agricultural Improvement and Science around 1800. In accordance with some historians of philosophy, this paper claims that Kant's critical philosophy can be seen as a watershed between the largely negative and ascriptive term 'empiric' applied during the early modern period and the more self-referential term 'empiricist' of the modern period. I will examine the usage and polemical function of the 'empirical' label in German agricultural improvement, and will point out its largely negative connotation with respect to agricultural knowledge before 1810. I will then go on to demonstrate how the most prominent founding figure of modern agricultural science in Germany, Albrecht Daniel Thaer (1752-1828), used the conceptual watershed moment as a means to his own academic and polemical ends. Whereas Thaer's opponents, cameralist authors such as Johann Beckmann (1739-1811) and Friedrich Benedict Weber (1774-1848), remained on one side of the watershed, Thaer's reasoning embraced both connotations of the 'empirical', and did so in significant ways. My conclusion is that the conceptual transition of the term reflects societal conflicts and social change on a broader level. Thus, the general historiographical claim of this paper is that conceptual histories are a useful and prolific tool of historical research.