Martin Heidegger (26 September 1889 – 26 May 1976) was a German philosopher whose work was central to the development of phenomenology, hermeneutics, and existentialism. He has had significant influence within subsequent philosophy, social sciences and humanities, and theology.
Heidegger's magnum opus, Being and Time (1927), is widely considered one of the most significant works of modern philosophy. In it, he introduced the concept of Dasein ("being-there") to describe the distinctive character of human existence, arguing that humans possess a "pre-ontological" understanding of being that shapes how they live and act, which he analyzed in terms of the unitary structure of "being-in-the-world". Through his analysis of Dasein, Heidegger sought to reawaken what he called "the question of being": the fundamental inquiry into what makes entities intelligible as the entities they are. In other words, Heidegger's governing "question of being" is concerned with what makes beings intelligible as beings. This question, he believed, had been neglected or obscured throughout the history of Western philosophy since the ancient Greeks.
His later work turned increasingly to questions of technology, language, art, and poetry, developing themes of human "dwelling" in the world and critiquing what he saw as the nihilistic trajectory of modern technological civilisation. Thinkers as varied as Jean-Paul Sartre, Hans-Georg Gadamer, Hannah Arendt, Jacques Derrida, Michel Foucault, Emmanuel Levinas, and Richard Rorty were substantially shaped by engagement with his thought, whether in agreement or opposition.
Heidegger's legacy has been complicated and shadowed by his involvement with Nazism. In April 1933, he was elected rector of the University of Freiburg and joined the Nazi Party, a membership he retained until 1945. The nature and extent of his commitment to Nazism, and the question of whether his philosophy is inherently connected to his political choices, remain subjects of significant scholarly controversy. After the war, he was banned from teaching following denazification proceedings, a ban later lifted in 1949, after which he returned to lecturing at the University of Freiburg. During this period of enforced withdrawal, he nevertheless continued to exert influence through private seminars and audiences at his home. His refusal to publicly repudiate his Nazi involvements or express remorse in unambiguous terms has continued to trouble interpreters of his work.
Heidegger was born on 26 September 1889 in rural Meßkirch, Baden, the son of Johanna (née Kempf) and Friedrich Heidegger. His father was the sexton of the village church, and the young Martin was raised Catholic.
In 1903, Heidegger began to train for the priesthood. He entered a Jesuit seminary in 1909, but was discharged within weeks because of heart trouble. It was during this time that he first encountered the work of Franz Brentano, the work of whom is credited as first sparking Heidegger's interest in the question of Being, specifically in regard to Brentano's thesis On the Manifold Sense of Being according to Aristotle. From here he went on to study theology and scholastic philosophy at the University of Freiburg.
In 1911, he broke off training for the priesthood and turned his attention to recent philosophy, in particular, Edmund Husserl's Logical Investigations. He graduated with a thesis on psychologism, The Doctrine of Judgment in Psychologism: A Critical-theoretical Contribution to Logic, in 1914. The following year, he completed his habilitation thesis on Duns Scotus, which was directed by Heinrich Rickert, a neo-Kantian, and influenced by Husserl's phenomenology. The title has been published in several languages and in English is Duns Scotus's Doctrine of Categories and Meaning.
He attempted to get the (Catholic) philosophy post at the University of Freiburg on 23 June 1916 but failed despite the support of Heinrich Finke. Instead, he worked first as an unsalaried Privatdozent then served as a soldier during the final year of World War I. His service was in the last ten months of the war, most of which he spent in a meteorological unit on the western front upon being deemed unfit for combat.
From 1919 to 1923, Heidegger taught courses at the University of Freiburg. At this time he also became an assistant to Edmund Husserl, who had been a professor there since 1916.
In 1923, Heidegger was elected to an extraordinary professorship in philosophy at the University of Marburg. His colleagues there included Rudolf Bultmann, Nicolai Hartmann, Paul Tillich, and Paul Natorp. Heidegger's students at Marburg included Hans-Georg Gadamer, Helene Weiss, Karl Löwith, Hannah Arendt, Gerhard Krüger, Leo Strauss, Jacob Klein, Günther Anders, and Hans Jonas. Following Aristotle, he began to develop in his lectures the main theme of his philosophy: the question of the sense of being. He extended the concept of subject to the dimension of history and concrete existence, which he found prefigured in such Christian thinkers as Paul of Tarsus, Augustine of Hippo, Martin Luther, and Søren Kierkegaard. He also read the works of Wilhelm Dilthey, Husserl, Max Scheler, and Friedrich Nietzsche.
In 1927, Heidegger published his main work, Sein und Zeit (Being and Time). He was primarily concerned in qualifying to be a full professor. The book, however, did more than this: it raised him to "a position of international intellectual visibility."
When Husserl retired as professor of philosophy in 1928, Heidegger accepted Freiburg's election to be his successor, in spite of a counteroffer by Marburg. The title of his 1929 inaugural lecture was "What is Metaphysics?" In this year he also published Kant and the Problem of Metaphysics.
Heidegger remained at Freiburg im Breisgau for the rest of his life, declining later offers, including one from Humboldt University of Berlin. His students at Freiburg included Günther Anders, Hans Jonas, Karl Löwith, Charles Malik, Herbert Marcuse, and Ernst Nolte. Emmanuel Levinas attended his lecture courses during his stay in Freiburg in 1928, as did Jan Patočka in 1933; Patočka, in particular, was deeply influenced by him.
Heidegger was elected rector of the university on 21 April 1933; he joined the Nazi Party on 1 May, just three months after Adolf Hitler was appointed chancellor. During his time as rector he was a member and an enthusiastic supporter of the party. There is continuing controversy as to the relationship between his philosophy and his political allegiance to Nazism. He wanted to position himself as the philosopher of the party, but the highly abstract nature of his work and the opposition of Alfred Rosenberg, who himself aspired to act in that position, limited Heidegger's role. His withdrawal from his position as rector owed more to his frustration as an administrator than to any principled opposition to the Nazis, according to historians. In his inaugural address as rector on 27 May he expressed his support of a German revolution, and in an article and a speech to the students from the same year he also vocalized support for Adolf Hitler. In November 1933, Heidegger signed the Vow of allegiance of the Professors of the German Universities and High-Schools to Adolf Hitler and the National Socialistic State. Heidegger resigned from the rectorate in April 1934 and pursued a teaching agenda aligned with Nazi cultural politics until 1945.
In 1935, he gave the talk "The Origin of the Work of Art". The next year, while in Rome, Heidegger gave his first lecture on Friedrich Hölderlin. In the years 1936–1937, Heidegger wrote what some commentators consider his second greatest work, Contributions to Philosophy; it would not be published, however, until 1989, 13 years after his death.
From 1936 to 1940, Heidegger also delivered a series of lectures on Friedrich Nietzsche at Freiburg that presented much of the raw material incorporated in his more established work and thought from this time. These would appear in published form in 1961. This period also marks the beginning of his interest in the "essence of technology".