Søren Aabye Kierkegaard ( , ; ; 5 May 1813 – 11 November 1855.) was a Danish philosopher, Christian theologian, poet, social critic, and religious author who is widely considered to be the first existentialist philosopher. He wrote critical texts on organized religion, Christianity, morality, ethics, psychology, love, and the philosophy of religion, displaying a fondness for metaphor, irony, and parables. Much of his philosophical work deals with the issues around how one lives as a "single individual", highlighting the importance of authenticity, personal choice and commitment, and the duty to love. Kierkegaard prioritized concrete human reality over abstract thinking.

Kierkegaard's theological work focuses on Socratic Christian ethics, the institution of the Church, the differences among purely objective proofs of Christianity, the infinite qualitative distinction between man and God, and the individual's subjective relationship to the God-Man Jesus Christ,Point of View by Lowrie, p. 41; ; Søren Kierkegaard 1847 Upbuilding Discourses in Various Spirits, Hong pp. 225–226; Works of Love IIIA, pp. 91ff. which came through faith.; Either/Or Vol II, pp. 14, 58, 216–217, 250. Much of his work deals with Christian love. He was extremely critical of the doctrine and practice of Christianity as a state-controlled religion (Caesaropapism), like the Church of Denmark. His psychological work explored the emotions and feelings of individuals when faced with life choices. Unlike Jean-Paul Sartre and the atheistic existentialism paradigm, Kierkegaard focused on Christian existentialism.

Kierkegaard's early work was written using pseudonyms, who presented distinctive viewpoints and interacted in complex dialogue. He wrote Upbuilding Discourses under his own name and dedicated them to the "single individual" who might want to discover the meaning of his works. He wrote: "Science and scholarship want to teach that becoming objective is the way. Christianity teaches that the way is to become subjective, to become a subject."Soren Kierkegaard, Works of Love, 1847 Hong 1995 p. 283. Kierkegaard emphatically denied that observation alone could reveal the inner workings of the world of the spirit.Philosophical Fragments and Concluding Postscript both deal with the impossibility of an objectively demonstrated Christianity, also Repetition, Lowrie 1941 pp. 114–115, Hong pp. 207–211.

Some of Kierkegaard's key ideas include the concept of "subjective and objective truths", the knight of faith, the recollection and repetition dichotomy, angst, the infinite qualitative distinction, faith as a passion, and the three stages on life's way. Kierkegaard wrote in Danish and the reception of his work was initially limited to Scandinavia, but by the turn of the 20th century his writings were translated into French, German, and other major European languages. By the middle of the 20th century, his thought exerted a substantial influence on philosophy,Stewart, Jon (ed.) Kierkegaard's Influence on Philosophy, Volume 11, Tomes I–III. Ashgate, 2012. theology,Stewart, Jon (ed.) Kierkegaard's Influence on Theology, Volume 10, Tomes I–III. Ashgate, 2012. and Western culture in general.Stewart, Jon (ed.) Kierkegaard's Influence on Literature and Criticism, Social Science, and Social-Political Thought, Volumes 12–14. Ashgate, 2012.

Early years (1813–1836)

Kierkegaard was born to an affluent family in Copenhagen as the youngest of seven children. His mother, Ane Sørensdatter Lund Kierkegaard (1768–1834), had served as a maid in the household before marrying his father, Michael Pedersen Kierkegaard (1756–1838). She was an unassuming figure: quiet, and not formally educated. Her granddaughter, Henriette Lund, wrote that she "wielded her scepter with delight, cosseted them [Søren and his brother Peter], and protected them like a hen her chicks". She also wielded influence on her children so that later Peter Christian Kierkegaard said that his brother preserved many of their mother's words in his writings. His father, on the other hand, was a devoutly Christian well-to-do wool merchant from Jutland. He was a "very stern man, to all appearances dry and prosaic, but under his 'rustic cloak' demeanor he concealed an active imagination which not even his great age could blunt".Johannes Climacus by Søren Kierkegaard, p. 17 He was also interested in philosophy and often hosted intellectuals at his home. He was devoted to the rationalist philosophy of Christian Wolff, and he eventually retired partly to pursue more of Wolff's writings. Kierkegaard, who followed his father's beliefs as a child, was heavily influenced by Michael's devotion to Wolffian rationalism. He also enjoyed the comedies of Ludvig Holberg, the writings of Johann Georg Hamann, Gotthold Ephraim Lessing,Either/Or Part I Swenson, 1944, 1959 pp. 1967ff; Edward Young,Either/Or Part I title page, Stages on Life's Way, pp. 150, 216, 339 and Plato. The figure of Socrates, whom Kierkegaard encountered in Plato's dialogues, would prove to be a phenomenal influence on the philosopher's later interest in irony, as well as his frequent deployment of indirect communication.

Kierkegaard loved to walk along the crooked streets of 19th century Copenhagen, where carriages rarely went. In 1848, Kierkegaard wrote, "I had real Christian satisfaction in the thought that, if there were no other, there was definitely one man in Copenhagen whom every poor person could freely accost and converse with on the street; that, if there were no other, there was one man who, whatever the society he most commonly frequented, did not shun contact with the poor, but greeted every maidservant he was acquainted with, every manservant, every common laborer."The Point of View of My Work as An Author: A Report to History by Søren Kierkegaard, written in 1848, published in 1859 by his brother Peter Kierkegaard Translated with introduction and notes by Walter Lowrie, 1962, Harper Torchbooks, pp. 48–49 Our Lady's Church was at one end of the city, where Bishop Mynster preached the Gospel. At the other end was the Royal Theatre where Fru Heiberg performed.

Based on a speculative interpretation of anecdotes in Kierkegaard's unpublished journals, especially a rough draft of a story called "The Great Earthquake", some early Kierkegaard scholars argued that Michael believed he had earned God's wrath and that none of his children would outlive him. He is said to have believed that his personal sins, perhaps indiscretions such as cursing the name of God in his youth or impregnating Ane out of wedlock, necessitated this punishment. Though five of his seven children died before he did, both Søren and his brother Peter outlived him. Peter, who was seven years older, later became bishop in Aalborg. Julia Watkin thought Michael's early interest in the Moravian Church could have led him to a deep sense of the devastating effects of sin.

From 1821 to 1830, Kierkegaard attended the School of Civic Virtue, Østre Borgerdyd Gymnasium when the school was situated in Klarebodeme, where Kierkegaard studied Latin, Greek, and history, among other subjects. During his time there he was described as "very conservative"; someone who would "honour the King, love the church and respect the police". He frequently got into altercations with fellow students and was ambivalent towards his teachers. He went on to study theology at the University of Copenhagen. He had little interest in historical works, philosophy dissatisfied him, and he couldn't see "dedicating himself to Speculation".Johannes Climacus by Søren Kierkegaard, p. 29 He said, "What I really need to do is to get clear about "what am I to do", not what I must know." He wanted to "lead a completely human life and not merely one of knowledge".Kierkegaard's Journals Gilleleie, 1 August 1835. Either/Or Vol II pp. 361–362 Kierkegaard didn't want to be a philosopher in the traditional or Hegelian senseJohannes Climacus by Søren Kierkegaard, pp. 22–23, 29–30, 32–33, 67–70, 74–76 and he didn't want to preach a Christianity that was an illusion.Point of View by Lowrie, pp. 28–30 "But he had learned from his father that one can do what one wills, and his father's life had not discredited this theory."Johannes Climacus by Søren Kierkegaard, p. 23

One of the first physical descriptions of Kierkegaard comes from an attendee, Hans Brøchner, at his brother Peter's wedding party in 1836: "I found [his appearance] almost comical. He was then twenty-three years old; he had something quite irregular in his entire form and had a strange coiffure. His hair rose almost six inches above his forehead into a tousled crest that gave him a strange, bewildered look." Another comes from Kierkegaard's niece, Henriette Lund (1829–1909), who recounts that as a little boy Søren was "of a slight and delicate appearance. He went around in a coat the color of red cabbage, and his father usually called him 'the Fork,' because of his precocious tendency to make satirical remarks. Even though there was a serious, almost strict tone in the Kierkegaard home, I still have the impression that there was room for youthful liveliness, though perhaps of a more sober, homemade sort than is usual today. In the same way the house was also open, with an old-fashioned kind of hospitality." He was also described as "quaintly attired, slight and small".

Kierkegaard's mother "was a nice little woman with an even and happy disposition," according to a grandchild's description. She was never mentioned in Kierkegaard's works. Ane died on 31 July 1834, age 66, possibly from typhus.Kierkegaard by Josiah Thompson, Published by Alfred P. Knoff, inc, 1973 pp. 14–15, 43–44 His father died on 8 August 1838, age 82. On 11 August, Kierkegaard wrote: "My father died on Wednesday (the 8th) at 2:00 a.m. I so deeply desired that he might have lived a few years more... Right now I feel there is only one person (E. Boesen) with whom I can really talk about him. He was a 'faithful friend.Journals & Papers of Søren Kierkegaard IIA 11 August 1838

Journals According to Samuel Hugo Bergmann, "Kierkegaard's journals are one of the most important sources for an understanding of his philosophy".Hugo Bergmann Dialogical Philosophy from Kierkegaard to Buber p. 2 Kierkegaard wrote over 7,000 pages in his journals on events, musings, thoughts about his works and everyday remarks.Given the importance of the journals, references in the form of (Journals, XYZ) are referenced from Dru's 1938 Journals. When known, the exact date is given; otherwise, month and year, or just year is given. The entire collection of Danish journals () was edited and published in 13 volumes consisting of 25 separate bindings including indices. The first English edition of the journals was edited by Alexander Dru in 1938. The style is "literary and poetic [in] manner".

Kierkegaard wanted to have Regine, his fiancée (see below), as his confidant, but considering this an impossibility, made his confidant "my reader, that single individual". His question was whether or not one can have a spiritual confidant. He wrote the following in his Concluding Postscript: "With regard to the essential truth, a direct relation between spirit and spirit is unthinkable. If such a relation is assumed, it actually means that the party has ceased to be spirit."

Kierkegaard's journals were the source of many aphorisms. The following passage, from 1 August 1835, is perhaps his most oft-quoted aphorism and a key quote for existentialist studies: