Søren Kierkegaard
Danish · 1813–1855
Danish philosopher, theologian, and cultural critic, widely regarded as the first existentialist thinker. Writing under a cast of fictional pseudonyms, Kierkegaard probed the inner life of the individual — despair, anxiety, faith, and authenticity — and famously coined the phrase "the leap of faith" to describe the only route out of the human predicament. Key works include Either/Or, Fear and Trembling, The Concept of Anxiety, and The Sickness Unto Death. A devout but heterodox Christian, his ideas later shaped Heidegger, Sartre, and twentieth-century existentialism.