In 1861, Ketteler published a book on reconciliation between Catholics and Protestants in Germany,
Freiheit, Autorität, und Kirche; in it, he proposed the founding of a prayer society "for the Reunion of Christendom". Ketteler was friends with
Julie von Massow, a Lutheran woman from Prussian nobility, who established one of these prayer societies. Ketteler was opposed the dogma of
papal infallibility on the ground that it was being promulgated at an inappropriate time. After the dogma was defined in 1870, he submitted to the decrees. In 1858, Ketteler issued a pamphlet on the rights of the Roman
Catholic Church in Germany, drawing a hard line between the Church and the State. In 1863 he adopted
Ferdinand Lassalle's views, and published his
Die Arbeitfrage und das Christenthum. He was a vocal opponent of the State in the
Kulturkampf provoked by Prince
Otto von Bismarck after the publication of the Vatican decrees, and was largely instrumental in compelling von Bismark to retract the pledge he had given to never "
go to Canossa." In 1874, Ketteler forbade his clergy from celebrating the anniversary of the
Battle of Sedan, and declared the
Rhine to be a "Catholic river." == Notes ==