Søren Aabye Kierkegaard was born in Copenhagen in 1813 and studied theology and philosophy at the University of Copenhagen. His early work examined irony and Socrates, and he later developed a distinctive form of writing combining philosophy, theology, literary criticism and religious reflection. Works including Either/Or, Fear and Trembling and The Concept of Anxiety often appeared under pseudonyms, allowing him to present contrasting viewpoints rather than a single systematic doctrine.

Kierkegaard focused on the individual’s relation to choice, responsibility, anxiety, despair and faith. He challenged aspects of Hegelian philosophy and criticised what he regarded as the complacency of established Christianity in Denmark. In his final years, he attacked the Danish state church more directly through newspaper articles and the pamphlet The Moment. He died in Copenhagen in 1855. His writings later became influential in existentialist philosophy, Christian theology, psychology and modern literature.