The idea of national philosophy carries in it a strange contradiction. We talk about 'German philosophy' or 'American philosophy'. But philosophy has always pictured itself to be the project of universality. It presents itself as something that takes place outside or beyond the national ultimately detachable from language, culture and history.
So why do we assign nationalities to philosophies? Building on Jacques Derrida's unpublished seminars on philosophical nationalism, Oisn Keohane claims that national philosophies are a variant of some form of cosmo-nationalism: a strain of nationalism that uses, rather than opposes, ideas in cosmopolitanism to advance the aims of one nation.