filioque in the 19th century

"76. The issue of unity and separation -- so emotionally, as well as intellectually, central to romanticism -- is marvelously presented in Khomiakov's fictitious account of an Orthodox traveler in Western lands who, when he hears the addition of filioque to the creed in the liturgy, discovers that the West has split from Christendom. (Polnoe sobranie sochinenii [Moscow, 1990-1914], vol. 2, pp. 48-49.) It is interesting that both Coleridge and Friedrich Schlegel considered filioque an important issue and championed the Western position against the Orthodox."

-- The Emergence of Romanticism, Nicholas V. Riasanovsky, 1992, p. 95, note 76.