“The idea of the British philosophers Berkeley and Hume that man did not passively observe and absorb knowledge, but rather by the process of observation created it and moulded the world through his own consciousness, had taken deep hold in Germany. Clausewitz did not need to read the works of his contemporary Kant (and there is no evidence that he did) to become familiar with these ideas which formed the basis of Kant’s philosophy. He had also absorbed those that had re-entered philosophical thought with the revival of Hellenism and were so powerfully to influence the work of the young Hegel: the Socratic distinctions between the ideal and its manifestations, between the absolute, unattainable concept and the imperfect approaches to it in the real world.”