Søren Kierkegaard's extensive catalogue of published and unpublished works had, both in Denmark and abroad, a profound influence on the theology, philosophy, and literature of the nineteenth and twentieth centuries. His religious philosophy, as well as his conflict-ridden relationship to the Danish State Church, not only greatly affected the Danish clergy but also served as an inspiration for Protestant and Catholic theology, as well as some Buddhist thought. Kierkegaard's existential philosophy and his break with the systematic idealism of the German philosopher Georg Wilhelm Friedrich Hegel were crucial for both German and French existentialism, as well as for the Scandinavian writers of the Modern Breakthrough, whose main figures--the critic Georg Brandes and the playwrights Henrik Ibsen and August Strindberg--influenced as they were by Kierkegaard's acute psychological analysis, took as the basis for their work his understanding of the individual, despite their rejection of his Christianity. Through...