1813–1855
Søren Kierkegaard
The Dane Søren Kierkegaard earned a theology degree in 1840 and broke his engagement to Regine Olsen in 1841. He saw his calling as making Christianity difficult again and attacked the "Christendom" that had turned faith into a mere game of being Christian. He wrote his works (Fear and Trembling, Philosophical Fragments, etc.) under pseudonyms, having rejected Hegel's "System." In 1854–1855 he openly attacked the official Danish church and its clergy.
Almost unheard in his own century, he is regarded as the founder of existentialism and strongly influenced the young Karl Barth.