The idea of nation, i.e. the idea of a radical difference among popular communities, as Federico Chabod writes, asserts itself paradoxically in the late XVII century, between Rousseau and Herder, within the scope of a culture which sets up cosmopolitism as ground of its action. Romantic culture gave emphasis to the point of view of nationality, on the one hand in supporting and justifying popular revolt for the independence, on the other trough the ambiguous theories of “supremacies”, nationalism and struggles among nations. The process of development of this idea from the XVIII century reflects the development of the philosophical speculation which begins whit the idealism of Kant and the derivation from it of more and more radical forms of idealism. The dynamics between speculation and political action reaches its full consciousness already by Fichte: he is the one who binds together the revolution which he completed in thought with his Wissenschaftslehre and the historical event of the French Revolution