  In the late 1780s, before his encounter with Reinhold, Rehberg took part in some of the heated debates surrounding Kant's critical philosophy.  He was both an admirer and critic of Kant.  While he defended Kant against the polemics of the Wolffians, he also wrote a critical review of the second Kritik, which was widely read in his  day.[41]  But the review of the second Kritik was only the first skirmish of a greater battle.  Rehberg realized that his case against revolutionary ideology could triumph only if he defeated Kant.  For Kant's ethical rationalism gave a strong philosophical foundation for the doctrines of Rousseau, which had been such an inspiration for the radicals in France.  Some of Kant's basic concepts—the categorical imperative and moral autonomy— seemed post facto rationalization for Rousseau's social contract theory and republicanism.  What was only a feeling or intuition in Rousseau became a concept or principle in Kant.  These implications of Kant's doctrines became explicit in 1793 when Kant published his famous ‘Theory-Practice’ essay in the Berlinische  Monatsschrift.[42]  Here Kant argued that there is no gap between theory and practice in politics, and that reason is practical in political as well as moral life.  He maintained that the principles of morality, which are determined by pure reason alone, are also binding in politics, and that pure reason provides the basis for a republican constitution involving the principles of liberty, equality and independence.  Kant's theses were a direct challenge to Rehberg, who had made the gap between theory and practice the leitmotif of his critique of the Revolution.  Sooner or later, then, he would have to reckon with the sage of Königsberg.  His reply to Kant duly appeared in the Berlinische Monatsschrift in February  1794.[43] 