Søren Aabye Kierkegaard (b.1813, d. 1855) was a profound and prolific writer in the Danish "golden age" of intellectual and artistic activity. His work crosses the boundaries of philosophy, theology, psychology, literary criticism, devotional literature and fiction. Kierkegaard brought this potent mixture of discourses to bear as social critique and for the purpose of renewing Christian faith within Christendom. At the same time he made many original conceptual contributions to each of the disciplines he employed. He is known as the "father of existentialism", but at least as important are his critiques of Hegel and of the German romantics, his contributions to the development of modernism, his literary experimentation, his vivid re-presentation of biblical figures to bring out their modern relevance, his invention of key concepts which have been explored and redeployed by thinkers ever since, his interventions in contemporary Danish church politics, and his fervent attempts to analyse and revitalise Christian faith. Kierkegaard burned with the passion of a religious poet, was armed with extraordinary dialectical talent, and drew on vast resources of erudition.