Duty is for Kant the One and All. Out of the duty of gratitude, he claims, one has to defend and esteem the ancients; and only out of duty has he become a great man.

At a later period he was councillor of legation in the Austrian embassy at the Frankfurt diet but in 1818 he returned to Vienna. Schlegel et la genie du romantisme allemand (1904); by the same Erläuterungen In F. Culture et traduction dans l'Allemagne romantique: Herder Goethe Schlegel Novalis Humboldt Schleiermacher Hölderlin.

With his older brother August Wilhelm Schlegel he was a critical leader of German Romanticism.