Martin Heidegger

1. Introduction

Martin Heidegger (1889–1976) was a German philosopher whose work reoriented 20th‑century Continental thought around the question of Being (Sein). Trained initially in Catholic theology and neo‑Kantian philosophy, he became a central figure in phenomenology, transforming it from a method of describing consciousness into a historical and existential inquiry into the ways in which beings are disclosed.

His most influential book, Being and Time (1927), proposes an existential analytic of Dasein—human existence understood as “being‑there”—as the privileged route to reviving the neglected question of the meaning of Being. Later writings move away from this focus on Dasein toward the history of Being (Seinsgeschichte), the role of language and poetry, and a far‑reaching critique of modern technology.

Heidegger’s career is also marked by profound controversy. His membership in the National Socialist (Nazi) Party, his rectorship at the University of Freiburg (1933–34), and antisemitic passages in his posthumously published Black Notebooks have generated enduring ethical and interpretive debates about the relation between his philosophy and his politics.

The entry that follows situates Heidegger’s thought in its biographical and historical context, outlines the main phases of his intellectual development, and presents the core themes of his philosophy—Being, Dasein, temporality, language, art, technology, and human existence—alongside major lines of reception and criticism. Throughout, it distinguishes between Heidegger’s own formulations and the diverse ways in which scholars and critics have interpreted, extended, or rejected them.

2. Life and Historical Context

Heidegger’s life spans the collapse of the German Empire, two world wars, the rise and fall of National Socialism, and the division of postwar Europe. Many interpreters treat these upheavals as inseparable from the development and reception of his philosophy.

Biographical outline and political milieu

Biographers emphasize that Heidegger’s rural Swabian Catholic upbringing and his attachment to his hometown Meßkirch and later Todtnauberg cabin inform his recurring themes of rootedness, dwelling, and earth. At the same time, his intellectual career unfolded in elite German universities deeply affected by political turmoil.

Contextual interpretations

Scholars disagree on how tightly his philosophy is bound to this historical environment:

• One line of interpretation, found in studies by historians of ideas, stresses the impact of post‑WWI disillusionment, economic crisis, and the perceived collapse of traditional values on Heidegger’s early focus on anxiety, finitude, and authenticity.
• Others emphasize the continuities between Heidegger’s critique of modern technology and broader interwar critiques of modernity, nationalism, and “rootlessness” in German culture.
• A contrasting view highlights the relative autonomy of philosophical problems—such as the ontological difference and the history of metaphysics—from day‑to‑day politics, holding that Heidegger’s concepts cannot be simply reduced to reflections of his time.

Postwar debates often turn on whether Heidegger’s involvement with National Socialism is rooted in a specifically German conservative–revolutionary milieu, in structural features of his ontology, or in personal misjudgment and ambition. These questions frame much of the subsequent discussion of his life and work.

3. Education, Early Influences, and Academic Career

Heidegger’s formation combines Catholic theology, neo‑Kantianism, and phenomenology, and his early academic trajectory sets the stage for Being and Time.

Theological and philosophical training

Heidegger entered a Jesuit novitiate briefly and then studied Catholic theology in Freiburg (1909–1911) before switching to philosophy, mathematics, and natural sciences. Early writings engage Scholastic thinkers (notably Duns Scotus and Thomas Aquinas) and the neo‑Scholastic revival. Proponents of a continuity thesis see enduring traces of these interests in his later concern with Being, ontological difference, and the critique of onto‑theology.

Under Heinrich Rickert, a leading neo‑Kantian, Heidegger completed his doctoral dissertation (1913) and habilitation (1915). His work during this period wrestles with neo‑Kantian issues of value, objectivity, and methodology. Some interpreters highlight his growing dissatisfaction with neo‑Kantian formalism as a catalyst for his move to phenomenology.

Encounter with Husserl and phenomenology

From 1916 Heidegger served as assistant to Edmund Husserl in Freiburg. Husserl’s phenomenological method—“to the things themselves”—offered an alternative to both neo‑Kantianism and historicism. Heidegger adopted phenomenological description but reoriented it toward what he called the facticity of life and the “hermeneutics of factical life,” emphasizing historically situated existence rather than transcendental structures of consciousness.

Academic positions and early teaching

Lectures from the Freiburg and early Marburg years, published posthumously, show Heidegger developing key themes: being‑in‑the‑world, care (Sorge), and temporality. Students such as Hans-Georg Gadamer, Hannah Arendt, and Karl Löwith later recalled these lectures as decisive turning points in German philosophy.

There is disagreement about how sharply to distinguish Heidegger’s “early” academic phase from his later thought. Some stress a relatively continuous deepening of questions already present in these lectures; others argue for a significant break (the Kehre) rooted partly in his changing institutional and political circumstances.

4. The Marburg Years and the Gestation of Being and Time

Heidegger’s appointment to Marburg (1923–1928) is widely regarded as the crucible in which Being and Time took shape.

Intellectual environment at Marburg

Marburg was a major center of neo‑Kantianism under Hermann Cohen and Paul Natorp, but by the 1920s it was also home to figures such as Rudolf Bultmann (New Testament theology) and, intermittently, Nicolai Hartmann. Heidegger’s teaching attracted large numbers of students across philosophy and theology, including Gadamer and Arendt.

Scholars note that Marburg’s theological faculty, especially Bultmann, encouraged Heidegger’s exploration of existential interpretation of scripture and early Christian life. This context informs the emphasis in Being and Time on factical life experience, guilt, and decision, even though the work presents itself as a strictly philosophical ontology.

Lecture courses and the path to Being and Time

In Marburg Heidegger delivered influential courses on Aristotle, Augustine, and phenomenological method. These lectures contain drafts of later sections of Being and Time:

• Analyses of worldhood and being‑in‑the‑world grow out of close readings of Aristotle’s Physics and Nicomachean Ethics.
• Discussions of anxiety, conscience, and resoluteness draw on Augustine’s Confessions and Luther’s interpretation of Paul, reworked in secular, ontological terms.

Some commentators, especially those focusing on theological resonances, argue that Being and Time is best read against this Marburg background as a radicalized “existential theology without God.” Others downplay these influences, stressing instead Heidegger’s engagement with Husserl and with the history of ontology.

Composition and unfinished character

Heidegger composed Being and Time between roughly 1923 and 1927, publishing it as a projected first half of a larger work. The second half, announced but never completed, was to undertake a destruction (Destruktion) of the history of ontology. Interpretations differ on why it remained unfinished:

• One view holds that Heidegger discovered intrinsic limitations in the existential analytic of Dasein, leading toward the later “turn.”
• Another suggests more practical or institutional reasons, including teaching loads and publishing pressures, without positing a decisive conceptual rupture.

In any case, the Marburg years mark the period in which Heidegger’s early phenomenology of factical life crystallized into the systematic project of Being and Time.

5. Heidegger and National Socialism

Heidegger’s involvement with National Socialism is one of the most contested aspects of his life and a central issue in assessing his work.

Party membership and rectorship

Heidegger joined the Nazi Party (NSDAP) in May 1933 and was appointed Rector of the University of Freiburg shortly thereafter. His inaugural Rectoral Address (“The Self‑Assertion of the German University”) employed philosophical language of historical destiny, leadership, and spiritual mission in support of the “revolution” of National Socialism.

During his rectorship (1933–34), Heidegger implemented elements of Nazi policy at the university, including aspects of Gleichschaltung (coordination). He resigned the rectorship in April 1934 but remained a party member until 1945.

Interpretive debates

Scholarly interpretations vary widely:

Some argue that key concepts in the early 1930s—especially historical destiny (Geschick) and the call for a “spiritual” renewal of the people—resonate with National Socialist rhetoric. Others counter that Heidegger’s philosophical vocabulary, while politically misused, cannot be equated with Nazi ideology and that he never endorsed core doctrines such as biological racism in his published works.

Postwar assessments and documents

Post‑1945, Heidegger underwent denazification and was banned from teaching until 1949. His own retrospective comments, including in interviews and the Spiegel conversation (published posthumously), often downplayed his political engagement, emphasizing a more general critique of modern technology and world‑ordering powers.

The publication of the Black Notebooks (private journals from the 1930s–40s) added further controversy, containing critical remarks about “world Jewry” and modernity. Some scholars interpret these as evidence of a philosophically motivated antisemitism; others argue they reflect a broader, problematic critique of globalization and calculative thinking rather than a systematic racial doctrine. Section 14 below surveys these debates in more detail.

6. Intellectual Development and the Kehre

The term Kehre (“turn”) is Heidegger’s own name for a shift in his thinking, especially from the late 1920s onward. How to understand this turn is a central issue in Heidegger scholarship.

From Dasein to the history of Being

In Being and Time, Heidegger approaches the question of Being through an analysis of Dasein, whose structures of care, temporality, and being‑in‑the‑world are to provide access to the meaning of Being. From the 1930s, however, his focus moves toward the history of Being (Seinsgeschichte), in which Being itself is said to unfold in historical “epochs” of revealing and concealment.

Heidegger describes this not as an abandonment but as a “twisting free” of the question of Being from its initial starting point. Later works emphasize:

• The withdrawal of Being and the “oblivion” of the ontological difference in Western metaphysics.
• The role of language and poetry as sites where Being “speaks.”
• Concepts such as Ereignis (appropriation/enowning) and Gestell (enframing).

Competing interpretations of the Kehre

Those emphasizing continuity point to Being and Time’s focus on temporality, thrownness, and the historicity of Dasein as early forms of the later concern with the historical “sending” of Being. Others highlight stylistic and conceptual changes—dense neologisms, appeals to “the gods,” and an intensified critique of modernity—as evidence of new departures, possibly connected to his political experiences.

Heidegger himself retrospectively suggested that even Being and Time already bore the mark of the Kehre, but that this “turning” became explicit only later. This self‑interpretation is accepted by some commentators and treated with caution by others, who see it as part of his attempt to shape his own legacy.

7. Major Works and Their Contexts

Heidegger’s oeuvre is extensive, comprising lectures, treatises, and essays. The following overview highlights key works and the contexts in which they emerged.

Selected major works

Contextual emphases

Interpreters often group these works into phases:

• Early phase: Being and Time and related lectures, shaped by phenomenology and existential concerns.
• Middle 1930s: works like Introduction to Metaphysics and Origin of the Work of Art articulate the Kehre and intersect with Heidegger’s political entanglements.
• Later phase: postwar texts on language, poetry, technology, and dwelling present a more meditative style.

There is debate over how central unpublished works like Contributions to Philosophy should be in interpreting Heidegger. Some view them as the “secret center” of his later thought, while others prioritize the more accessible published essays that shaped his historical influence.

8. Core Philosophy: Being, Dasein, and the Ontological Difference

Heidegger’s core philosophical project is to reopen the question of the meaning of Being, which he claims has been forgotten or obscured in Western metaphysics.

Being and the ontological difference

Heidegger distinguishes between beings (Seiendes)—entities such as objects, persons, numbers—and Being (Sein), the way in which beings are. This is the ontological difference. Traditional metaphysics, he argues, has tended to treat Being as if it were a highest being (God, substance, idea), thereby collapsing this difference.

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“The question of the meaning of Being must be posed again.”

— Heidegger, Being and Time, §1

Proponents of Heidegger’s approach credit him with uncovering a level of inquiry that underlies both empirical science and traditional ontology. Critics sometimes contend that the distinction is obscure or that it rephrases older metaphysical questions in new terminology.

Dasein and the existential analytic

To pose the question of Being, Heidegger begins from Dasein, the being for whom its own Being is an issue. Dasein is characterized by:

• Being‑in‑the‑world: a prior immersion in a meaningful context, rather than a subject confronting objects.
• Care (Sorge): Dasein’s existence is structured by concernful involvement with possibilities, others, and things.
• Thrownness and projection: Dasein finds itself already in a situation (thrown) while projecting itself toward future possibilities.

Heidegger calls the categories that describe Dasein’s mode of Being existentials (as opposed to traditional categorial determinations of objects). The “existential analytic” of Being and Time is meant as a preparatory step: by clarifying the Being of Dasein, we gain access to the meaning of Being in general.

Perspectives on the centrality of Dasein

Interpretations diverge on whether Dasein remains central across Heidegger’s oeuvre:

Subsequent sections elaborate how these core ideas are elaborated through analyses of temporality, language, art, and technology.

9. Temporality, Finitude, and Authenticity

In Being and Time, Heidegger argues that temporality is the key to understanding both Dasein and the meaning of Being.

Existential temporality

Heidegger distinguishes existential temporality from clock time. Dasein’s Being is “stretched along” between birth and death, structured by:

• Future (projection): Dasein projects possibilities.
• Past (having‑been): Dasein is thrown into a heritage and factical situation.
• Present (making‑present): Dasein engages with what is at hand.

Authentic temporality arises when these “ecstasies” form a unified horizon in which Dasein anticipates its own death.

Being‑toward‑death and finitude

Being‑toward‑death is Dasein’s anticipation of its ownmost, non‑relational, unsurpassable possibility. In anxiety before death, everyday securities fall away, revealing the null basis of Dasein’s projects. Proponents see this as a powerful analysis of human finitude, grounding a non‑metaphysical understanding of existence.

Critics have raised various concerns:

• Some existentialist readers emphasize the individualist and potentially heroic tone of authenticity.
• Theologians sometimes regard Heidegger’s account as secularizing religious ideas of finitude and eternity.
• Others argue that the analysis underplays social and material conditions.

Authenticity, inauthenticity, and the They

Heidegger differentiates authentic existence from inauthentic immersion in the They (das Man)—the anonymous norms and routines of everyday life. Inauthenticity is not a moral failing but a default mode in which Dasein “falls” into public interpretations.

Authenticity involves:

• Owning up to one’s finite possibilities.
• Hearing the call of conscience, which summons Dasein from lostness in the They to resolute self‑projection.

Interpretations diverge:

Later Heidegger retains the emphasis on finitude and historicity but increasingly situates them within the broader history of Being, rather than within individual self‑authorship alone.

10. Language, Poetry, and the House of Being

From the 1930s onward, Heidegger increasingly treats language as the primary site where Being is disclosed.

Language as the house of Being

In the Letter on Humanism, Heidegger writes:

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“Language is the house of Being. In its home human beings dwell.”

— Heidegger, Letter on Humanism

This slogan expresses several claims:

• Language is not merely a tool humans use; rather, it is the medium in which beings first appear as what they are.
• Human beings are “shepherds of Being” insofar as they listen and respond to this linguistic disclosure.

This view challenges representational theories of language that treat words as labels for pre‑given objects. Supporters see in Heidegger a precursor to later hermeneutics and deconstruction. Critics sometimes object that his conception is overly mystical or underplays communication and social practice.

Saying, showing, and the limits of representation

In later works collected in On the Way to Language, Heidegger distinguishes:

• Saying (Sage): the event of disclosure in which Being comes to presence.
• Talk and chatter: everyday language that can obscure this more originary saying.

Heidegger frequently uses etymology and wordplay to uncover forgotten possibilities of meaning in German and Greek. Some scholars view this as a rigorous “destruction” of inherited concepts; others see it as speculative or linguistically arbitrary.

Poetry and poets

Heidegger turns especially to poetry, above all Hölderlin, but also Rilke, Trakl, and others. For him, poetic language can bring forth a world, naming gods, earth, sky, and mortals in new ways.

Proponents argue that Heidegger shows how poetic texts articulate fundamental orientations toward Being that philosophy often overlooks. Critics contend that his readings sometimes subordinate poems to his own agenda or neglect historical and literary contexts.

Overall, the later Heidegger shifts the philosopher’s role from grounding knowledge to preparing a more receptive hearing for how Being speaks in and through language, particularly poetic saying.

11. Art, Truth, and Worldhood

Heidegger’s aesthetics—most prominently in The Origin of the Work of Art—reframes art as a site of truth rather than mere representation or subjective expression.

Art as setting‑to‑work of truth

Heidegger understands truth as unconcealment (aletheia): the coming‑into‑the‑open of beings as what they are. In this sense:

• A work of art is a place where a world is opened and earth is set forth.
• “World” denotes a historically specific horizon of meaning (e.g., Greek temple, medieval church).
• “Earth” refers to the self‑secluding dimension of materiality and mystery that resists total disclosure.

In the famous discussion of a Greek temple, Heidegger claims the temple does not simply depict deities but gathers and articulates an entire world of practices, gods, and mortality.

Worldhood and strife

Artworks stage a strife between world and earth: the world strives to shine forth; earth resists full transparency. This productive tension is seen as the site where a people’s self‑understanding is articulated.

Supporters of this view emphasize its departure from subjectivist aesthetics and its influence on later hermeneutics and critical theory. Critics raise concerns that linking art to a people’s “historical destiny” risks politicization or cultural essentialism.

Relations to other theories of art

Subsequent thinkers, including Gadamer and Derrida, have drawn on Heidegger’s linkage of art and truth while criticizing aspects of his language of origin, destiny, and rootedness. Debates also concern whether Origin should be read in light of his political commitments in the mid‑1930s or as a largely independent ontological inquiry.

12. Technology, Enframing, and Modernity

Heidegger’s philosophy of technology, chiefly articulated in The Question Concerning Technology, has been influential well beyond philosophy.

Essence of technology

Heidegger distinguishes between technological devices (machines, tools) and the essence of technology:

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“The essence of technology is by no means anything technological.”

— Heidegger, The Question Concerning Technology

He names this essence Gestell (enframing), a mode of revealing in which beings are ordered as standing‑reserve (Bestand)—resources available for optimization and control. Modern technology thus represents a historical configuration of the disclosure of Being, not a neutral set of instruments.

Danger and saving power

Heidegger characterizes Gestell as a danger: by reducing beings (including humans) to resources, it obscures other ways of relating to Being. Yet he also famously asserts that “where danger is, grows the saving power,” suggesting that recognizing the totalizing character of enframing may awaken alternative modes of revealing, for example in art or poetic dwelling.

Interpretations differ:

Modernity, science, and control

Heidegger links modern technology to modern science and to a long history of metaphysics that treats beings as objects for calculation. His analysis has been compared to, and sometimes criticized by, critical theorists (e.g., Adorno, Habermas) and philosophers of technology who emphasize social, economic, or political factors.

Supporters claim that Heidegger provides a deep account of how modernity’s drive for control shapes experience at a fundamental level. Critics argue that his focus on “epochal” destinings overlooks human agency, democratic deliberation, and the possibility of designing technologies differently within modernity.

13. Ethics, Politics, and the Human Being

Heidegger did not develop a systematic ethics or political philosophy in the conventional sense, leading to divergent assessments of his implications for these domains.

Critique of humanism and subjectivity

In Letter on Humanism, Heidegger criticizes traditional humanism for treating the human being as a rational subject at the center of beings. He proposes instead that humans are the “shepherds of Being”:

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“The human being is not the lord of beings. The human being is the shepherd of Being.”

— Heidegger, Letter on Humanism

On this view, ethics would not consist primarily in rules or values but in safeguarding an open space for the disclosure of Being. Proponents see this as a move beyond anthropocentrism toward a more modest, responsive conception of human existence.

Critics, however, argue that this framework is too indeterminate to guide action, risks quietism, or fails to address concrete issues of justice and power.

Implicit ethics and responsibility

Some interpreters discern an implied ethics in Heidegger’s analyses of:

• Authenticity and conscience (responsibility for one’s own finite existence).
• Care and solicitude (relations to others in the world).
• Dwelling (a respectful, non‑dominating relation to earth and others).

Environmental philosophers, for example, have drawn on his notion of dwelling to articulate ecological responsibility. Others, particularly from feminist and postcolonial perspectives, question whether his concepts can adequately account for embodiment, gender, or structural oppression.

Politics and the question of community

Heidegger’s reflections on historicity and the people (Volk), especially in the 1930s, have been read as gesturing toward a communitarian or even decisionist politics. Some argue that his emphasis on collective historical destiny contributed to his attraction to National Socialism. Others hold that later notions of “the people” become more indeterminate, referring to any community capable of a new relation to Being.

There is no consensus on whether Heidegger’s ontology is compatible with liberal democracy, socialism, or any specific political program. Many commentators maintain that his work offers diagnostic tools for understanding modernity rather than normative political prescriptions, while others insist that any philosophical account of human existence inevitably bears political implications that must be critically examined.

14. Reception, Criticism, and the Question of Antisemitism

Heidegger’s reception is marked by both profound influence and sharp controversy, particularly concerning antisemitism and his relation to National Socialism.

Philosophical reception

Heidegger has influenced:

• Existentialism (Sartre, though Heidegger later criticized Sartre’s humanism).
• Hermeneutics (Gadamer’s philosophical hermeneutics).
• Deconstruction (Derrida’s reworking of destruction and différance).
• Theology, environmental philosophy, and critical theory.

Some traditions, particularly analytic philosophy, long remained skeptical, criticizing his style as obscure or his arguments as insufficiently rigorous, though interest has grown in recent decades.

The question of antisemitism

Debate over Heidegger’s antisemitism intensified with the publication of his Black Notebooks. These notebooks contain disparaging remarks about “world Jewry,” sometimes linking it to modern calculative thinking and rootlessness.

Interpretive positions include:

Some scholars argue that Heidegger’s portrayal of modernity as dominated by calculative thinking and uprootedness echoes common antisemitic stereotypes of the time, thereby implicating his philosophical critique. Others maintain that his primary targets are broader phenomena (e.g., global technology, Americanism, Bolshevism) and that his occasional remarks about Jews, while reprehensible, are not philosophically foundational.

Ongoing critical debates

Heidegger’s Nazi engagement and antisemitic comments have led some institutions and scholars to question his place in the philosophical canon, while others argue for continued critical engagement with his work. Approaches vary:

• Separatist: distinguish sharply between philosophical insights and political failings.
• Integrative critical: read the philosophy and politics together, asking where they intersect.
• Rejectionist: hold that the political and antisemitic elements so compromise his thought that it should not be a major reference point.

These debates continue to shape Heidegger scholarship, influencing how his texts are taught, translated, and interpreted.

15. Legacy and Historical Significance

Heidegger’s legacy is both extensive and contested, encompassing major philosophical movements and broader cultural debates.

Influence across disciplines and traditions

Heidegger’s reorientation of phenomenology has had lasting effects on:

• Continental philosophy: existentialism, hermeneutics, deconstruction, post‑structuralism, and phenomenology of embodiment.
• Theology: both Catholic and Protestant thinkers have engaged his analyses of finitude, revelation, and language.
• Literary theory and aesthetics: his notions of worldhood, text, and interpretation inform structuralist and post‑structuralist approaches.
• Environmental and technology studies: his critique of Gestell and idea of dwelling influence ecological thought and philosophy of technology.

In analytic philosophy, his impact is more limited but evident in comparative work on metaphysics, temporality, and the philosophy of mind, as well as in renewed interest in conceptual engineering and ontological commitment.

Historical placement

Heidegger is often situated alongside figures such as Husserl, Wittgenstein, and Russell as a defining 20th‑century thinker. His attempt to “overcome metaphysics” and rethink Being has been seen as emblematic of a broader post‑metaphysical turn in philosophy.

At the same time, his political involvement and antisemitic remarks have made him a test case for questions about the relation between a thinker’s life and work. Some historians view Heidegger as a paradigmatic representative of the German crisis of modernity; others emphasize his role in inaugurating new modes of philosophical reflection that transcend that context.

Divergent assessments

Future scholarship continues to probe the internal development of Heidegger’s thought, reassess his political and cultural entanglements, and test the applicability of his concepts to contemporary problems—from digital technology and climate change to intercultural philosophy. His historical significance thus lies not only in what he taught but also in how the ongoing controversy around his work shapes reflection on philosophy’s responsibilities in the modern world.