To encounter the works of Martin Heidegger is often described as a struggle, a challenge that can feel both frustrating and profound. He is, without question, one of the most influential and respected philosophers of the 20th century, yet his writings remain notoriously difficult. He seems to pose far more questions than he answers, coining new words and imbuing existing terms with strange, unfamiliar meanings. This is made all the more complex by the fact that his magnum opus, Being and Time, was left unfinished, and he later expressed doubts about the very method he had pioneered.

Despite this, his influence is undeniable. Philosophers like Hans-Georg Gadamer saw themselves as his students, while Jean-Paul Sartre’s landmark work, Being and Nothingness, was written directly under the influence of Heidegger’s thought. There is no single, easy key to unlocking what Heidegger “really meant,” but by delving into his core ideas, we can begin to grasp the powerful vision that continues to captivate and challenge us.

The Question We Forgot to Ask

We go through our lives using the word “is” without a second thought. We say, “the book is on the table,” or “the sky is blue,” and we assume we understand precisely what we mean by “is.” Heidegger argues that this is the greatest oversight in the history of philosophy. Before we can ask what things exist, we must first confront a more fundamental question: What does it mean “to be” at all?

This is the central question of Being and Time. Heidegger saw that the concept of “Being” itself—not any particular being, but the very phenomenon of existence—had been forgotten. Philosophy had come to define it in various ways—as an idea, as substance, as reality—but it had stopped asking about its fundamental meaning. Heidegger believed that to find the answer, we couldn't look at objects. We had to look at the one entity for whom Being is a question: ourselves.

Dasein: The Being Who Cares

To get at the question of Being, Heidegger turns to the unique concept of Dasein. The German term, which literally translates to “being-there,” is often left untranslated because concepts like “existence” or “human consciousness” don’t quite capture its meaning.

Dasein is the kind of being that is capable of questioning its own existence. A rock or a tree simply is, but a human being understands that it exists. We are distinguished from all other beings by this unique capacity to comprehend and ask about the meaning of Being. Put simply, we are the only beings for whom our own being is an issue.

Heidegger also defines the essence of Dasein as “care.” This isn’t just an emotion, but a fundamental state of our existence. We find ourselves “thrown” into the world, not by our own choice, and from that moment on, we are forced to care for our existence. We must constantly project ourselves into the future, making choices and taking actions, because if we don't, our being will cease. The essence of a human being, therefore, is found in this ongoing, forward-looking process of living and caring for one's own life.

Being and Beings: The Shepherd and His Flock

So, what is the difference between “Being” and a “being”? They are not the same, yet one cannot exist without the other. Heidegger’s thought can be illuminated by a metaphor: imagine a flock of sheep in a pen. The sheep are all individual beings. If a shepherd is also in the pen, is he part of the flock? No. He is different from the sheep, yet his identity as a “shepherd” is entirely dependent on the flock. Without the sheep, he is no longer a shepherd; he is just a man.

In this metaphor, the flock represents all the concrete things that exist (tables, books, people)—these are all “beings.” Being itself is like the shepherd. It is not just another being among the others, but it is what allows beings to be what they are. At the same time, Being does not exist on its own, separate from the things that are. It is always the Being of beings, just as the shepherd is necessarily the shepherd of a flock.

Facing the Void: Death and Authentic Existence

For Dasein, for us, there is an ultimate limit: death. We can only ever understand death through the death of others; our own death is an event we can never experience and analyze, because by the time it happens, we are no longer there. Heidegger defines death with a characteristically challenging phrase: it is “the possibility of the impossibility of existence.”

What does this mean? For us, death is never a past or present reality. It is always a future possibility, the one possibility that will end all other possibilities. This fundamental fact about our existence presents us with a choice. We can live an “inauthentic” life, what Heidegger calls the life of das Man (“the they”). This is a life lost in everyday concerns, preoccupied with the present, where we try to be like everyone else and ignore the unsettling reality of our own finitude.

The alternative is an “authentic” existence. This means courageously confronting the fact of our eventual death. It involves what Heidegger calls “rushing forward toward oneself,” consciously living in anticipation of that final possibility. This awareness of our own limited time is what allows us to break free from the anonymous crowd and make real, meaningful choices about who we will be. The past is what has become real, shaping our present. The future is a field of potential, and it is in choosing which possibilities to make real that we define our existence.

The Shadow of the Black Notebooks

Heidegger’s philosophy was not the only ambiguous part of his life. His biography is marked by a dark and troubling chapter. In 2014, his “black notebooks”—diaries he kept from 1931 to 1941—were published. These confirmed what had long been known: Heidegger was a member of the National Socialist German Workers' Party and, for a time, an admirer of its leader. His political affiliations shocked and alienated many of his colleagues, including his own mentor Edmund Husserl and his friend Karl Jaspers.

After the war, the philosopher Herbert Marcuse wrote to Heidegger, urging him to publicly renounce his past actions. Heidegger replied that his later lectures already demonstrated his changed views on Nazism, but he never offered the clear, public apology many sought. For many, this leaves a permanent stain on his legacy. And yet, Heidegger’s philosophy itself contains no explicit political propaganda. It is a philosophy of being, detached from party or movement. It forces us to confront the uncomfortable possibility that a person can produce profound, timeless thought while simultaneously holding reprehensible political views. The facts of his life remain an inseparable and difficult part of his story.

References

• Heidegger, Martin. Being and Time. Translated by John Macquarrie & Edward Robinson, Harper & Row, 1962.
  This is Heidegger's foundational work. The introduction (especially pages 21-35) directly lays out his project of reawakening the "question of the meaning of Being," which he argues has been neglected by Western philosophy. It provides the primary context for the article's discussion of Being, Dasein, and care.
• Polt, Richard. Heidegger: An Introduction. Cornell University Press, 1999.
  This book serves as an exceptionally clear and accessible guide to Heidegger’s complex thought. Chapter 2, "The Human Way of Being," offers a brilliant explanation of Dasein, "thrownness," and "care" (pages 36-64). Chapter 4, "Death and Resolve," elaborates on the concepts of authenticity and inauthenticity (das Man), directly supporting the article's explanation of facing one's own mortality.
• Steiner, George. Heidegger. University of Chicago Press, 1991.
  Steiner provides a concise yet powerful overview of Heidegger's life and work for a general audience. The final chapter, "The Evil," directly addresses Heidegger's involvement with the Nazi party (pages 127-147). It offers a nuanced look at the controversy, his post-war silence, and the troubling relationship between the man's politics and his philosophy, reflecting the points made in the final section of the article.