Kierkegaard, Søren Aabye (söˈrən ôbˈü kyĕrˈkəgôr) [key], 1813–55, Danish philosopher and religious thinker. Kierkegaard's outwardly uneventful life in Copenhagen contrasted with his intensive inner examination of self and society, which resulted in various profound writings; their dominant theme is that "truth is subjectivity." Kierkegaard argued that in religion the important thing is not truth as objective fact but rather the individual's relationship to it. Thus it is not enough to believe the Christian doctrine; one must also live it. He attacked what he felt to be the sterile metaphysics of G. W. Hegel and the worldliness of the Danish church.
Kierkegaard's writings fall into two categories—the aesthetic and the religious. The aesthetic works, which include Either/Or (1843), Philosophical Fragments (1844), Stages on Life's Way (1845), and The Concluding Unscientific Postscript (1846), were all published under pseudonyms and interpret human existence through the eyes of various poetically delineated characters. In those works Kierkegaard developed an "existential dialectic" in opposition to the Hegelian dialectic, and described the various stages of existence as the aesthetic, the ethical, and the religious. As the individual advances through these stages he becomes increasingly more aware of his relationship to God. This awareness leads to despair as the individual realizes the antithesis between temporal existence and eternal truth. The specifically religious writings include Works of Love (1847) and Training in Christianity (1850). Kierkegaard also kept an extensive journal that contains many of his deepest insights. Although practically unknown outside Denmark during the 19th cent., he later exerted a tremendous influence upon both contemporary Protestant theology and the philosophic movement known as existentialism.
See N. Lebowitz, Kierkegaard: A Life of Allegory (1985); J. Walker, Kierkegaard: The Descent into God (1985); A. Hannay, Kierkegaard (1982) and Kierkegaard: A Biography (2001); J. Garff, Søren Kierkegaard: A Biography (2004); W. Lowrie, A Short Life of Kierkegaard (2013).