The German philosopher Johannes Clauberg (1622-1665) argued that German is supe- rior to Latin on account of its grammar and semantics and that it is, in fact, the best philosophical language. If all languages are not equivalent, it becomes relevant in which language one philosophises. This controversial position sets him apart from common ear- ly modern philosophical assumptions about language. Clauberg was also motivated by his German national sentiment. The paper suggests that Clauberg’s tentative ‘philosophy of German language’ is conceptually and historically important, at a time when philosophy in Latin was giving way to national vernacular traditions.