Søren Kierkegaard: The Father of Existentialism

There is a philosopher most people have never heard of who described your life more accurately than almost anyone who came after him.

He lived in Copenhagen in the 1800s. He never left Denmark. He was awkward, melancholic, deeply religious, and obsessed with a single question that he could not stop circling: what does it mean to exist as an individual?

Not as a category. Not as a member of a society or a church or a philosophical system. As a specific, irreducible, anxious, choosing human being.

His name was Søren Kierkegaard. He died in 1855 at forty-two, largely ignored. And then the twentieth century arrived, with its wars and its collapsed certainties and its desperate need for someone who had already thought seriously about what it means to be alive when nothing feels solid, and suddenly everyone was reading him.

Sartre built on him. Camus wrestled with him. Heidegger would not exist without him. Every major existentialist tradition traces back to this strange, lonely Dane who wrote half his books under fake names and spent his life thinking about what it costs to be a self.

This is his story. And more than that, this is his argument. Because Kierkegaard did not write history. He wrote diagnosis. And the condition he was diagnosing is still everywhere.

Søren Kierkegaard and Existentialism: Key Takeaways

• Kierkegaard is the founding father of existentialism, writing nearly a century before Sartre or Camus made the movement famous.
• His central obsession: the individual. Not humanity in the abstract, but the specific, anxious, choosing person who cannot hide behind systems or crowds.
• He identified three stages of existence: the aesthetic life, the ethical life, and the religious life. Most people, he argued, never make it past the first.
• His concept of the "leap of faith" is widely misunderstood. It is not about abandoning reason. It is about recognizing what reason alone cannot resolve.
• Kierkegaard diagnosed "the crowd" as the enemy of genuine selfhood, a diagnosis that feels more relevant now than it did in 1850.
• Anxiety, for Kierkegaard, is not a malfunction. It is the feeling of freedom, and the beginning of becoming who you actually are.
• Socratic AI was built for exactly the kind of individual Kierkegaard was writing for. The person who refuses to think in crowds.

The Man Himself

Kierkegaard's life was not glamorous. It was, by most external measures, a failure.

He was born in 1813 in Copenhagen, the youngest of seven children, to a father consumed by guilt over a sin he had committed in his youth and never fully named. That shadow fell over the whole family. Five of the seven children died young. Kierkegaard himself expected to die young and was surprised when he kept living.

He studied theology. He got engaged to a woman named Regine Olsen, whom he genuinely loved, and then broke off the engagement for reasons he never fully explained, perhaps because he felt his interior life was too dark and complicated to share, perhaps because he believed his calling required a kind of solitude that marriage would destroy. He spent the rest of his life writing about her indirectly in book after book.

He published prolifically, often under pseudonyms, different voices for different ideas, and was largely dismissed or mocked in Copenhagen during his lifetime. He died at forty-two after collapsing in the street, having spent almost everything he had on publishing his final works himself.

None of that tells you why he matters. What tells you why he matters is what he actually said.

The Problem Kierkegaard Was Solving

To understand Kierkegaard, you need to understand what he was reacting against.

The dominant philosophy of his era was Hegel's. And Hegel had built the most ambitious philosophical system in history, an attempt to explain everything, history, consciousness, society, spirit, as part of a single rational unfolding process. On Hegel's view, the individual was essentially a vehicle for something larger. History moved through people, not because of them.

Kierkegaard found this monstrous.

Not intellectually wrong, necessarily, though he thought it was that too. But existentially dishonest. Because you, sitting with this question right now, are not a vehicle for historical forces. You are a person who has to decide what to do with your life. You have to choose. You have to act. And no philosophical system, however grand and comprehensive, makes that choosing any easier or any less yours.

The system tells you what is rational. It does not tell you how to live. It does not tell you what to do when the rational thing and the thing your whole self is pulling toward are not the same thing. It does not tell you how to be a self, rather than just an instance of a category.

That gap, between the system and the individual, between the rational and the lived, is where Kierkegaard built his entire philosophy.

The Three Stages: Where Are You Living?

Kierkegaard's most famous idea is the three stages of existence. He called them spheres or stages of life, and he argued that most people live their entire lives in the first one without ever knowing there are others.

The Aesthetic Stage

The aesthetic life is the life organized around experience. Pleasure, sensation, novelty, beauty, excitement. The aesthetic person is always chasing the next thing that will make life feel vivid and alive.

This is not necessarily a shallow life. Kierkegaard's portrait of the aesthetic person, developed through his pseudonymous character "A" in Either/Or, is sophisticated and intelligent. The aesthete can appreciate art and beauty and irony. He is often charming, witty, and interesting.

But the aesthetic life has a structural problem. It depends entirely on external stimulation. The moment boredom arrives, the moment the novelty wears off, the moment there is nothing new to chase, the aesthetic person is left with nothing. Because they have built no interior life. They have only preferences, not commitments. Experiences, not character.

Kierkegaard saw this as the dominant mode of his era. He would see it as the dominant mode of ours. The endless scroll. The constant consumption of content. The optimization of life for interesting experiences rather than genuine depth. The aesthetic life, dressed in modern clothes, is everywhere.

Read about the meaning of life here.

The Ethical Stage

The ethical person has made a leap. They have recognized that life requires commitment, not just experience. They have chosen values, accepted obligations, built a consistent character that persists across time and circumstance.

The ethical life is organized around duty. Around becoming the kind of person who can be relied upon, who keeps their word, who takes responsibility seriously. It is the life of the person who has said: I am not just a series of experiences. I am a self with commitments that define me.

This is a genuine step forward. Most of what we call morality and civic virtue lives at the ethical stage. It is a serious and admirable way to live.

But Kierkegaard thought it was still not the deepest possible life. Because the ethical stage, for all its seriousness, still tries to resolve everything through reason and universal principle. And there are moments in human life that resist that resolution.

The Religious Stage

The third stage is the hardest to explain and the most misunderstood.

Kierkegaard is not saying that you need to go to church. He is saying that there are moments in life when you face a demand that no rational system can adjudicate for you. A moment where you must choose absolutely, with your whole self, on the basis of something that cannot be fully justified to anyone else.

His central example is Abraham and Isaac. God commands Abraham to sacrifice his son. From the ethical standpoint, this is straightforwardly wrong. No ethical principle justifies killing your child. And yet Abraham goes. Not because he has abandoned reason, but because he has encountered something that stands beyond the reach of any system.

Kierkegaard called this the teleological suspension of the ethical. The moment when the individual stands before an absolute demand and must respond with an absolute commitment that cannot be explained or justified from the outside.

You do not have to be religious to recognize this structure in human experience. There are choices in life, the ones that define you most completely, that cannot be made by consulting a rulebook. At some point, you have to leap.

The Leap of Faith: What It Actually Means

The leap of faith is the most famous and most misunderstood idea in Kierkegaard.

People use it to mean: abandon reason and just believe. That is not what he meant.

Kierkegaard was not anti-reason. He was pro-honesty about what reason can and cannot do. And what he saw was that the most important questions in human life, questions about how to live, what to commit to, who to be, cannot be resolved by reason alone. They require a leap, a moment of decisive commitment that goes beyond what the evidence strictly demands.

This is not irrationalism. It is realism about the limits of rationality. Every major commitment in life involves this structure. You cannot rationally prove in advance that a marriage will work. You cannot rationally prove that a career path is the right one. You cannot rationally prove that a set of values is worth organizing your life around. At some point, you commit. You leap.

What Kierkegaard wanted was for people to make that leap consciously, with full awareness of what they were doing, rather than drifting into commitments through habit or social pressure or the path of least resistance.

The opposite of the leap is not reason. It is evasion.

The Crowd: Kierkegaard's Most Devastating Idea

In 1846, Kierkegaard wrote something that reads like it was written last week.

"The crowd is untruth."

He meant something precise by this. The crowd, the aggregate of people following social consensus, peer opinion, conventional wisdom, is not a source of truth. It is a mechanism for avoiding individual responsibility.

When you think what everyone thinks, you do not have to think. When you believe what your group believes, you do not have to examine your beliefs. When you do what is socially expected, you do not have to choose. The crowd offers the enormous comfort of never having to be an individual.

Kierkegaard thought this was the deepest form of cowardice. Not because social consensus is always wrong, but because following it without examination means you have never actually owned your own life. You have borrowed it.

The antidote was not rebellion for its own sake. It was interiority. The cultivation of an inner life rich enough and examined enough that you could actually stand behind your own beliefs rather than sheltering in the crowd's.

In an era of social media, algorithmic feeds, viral opinion, and the constant pressure to perform belonging to the right groups, Kierkegaard's diagnosis of crowd-thinking is not historical. It is a live description of the current moment.

Read "Is AI making us dumber?"

Anxiety: The Dizziness of Freedom

One more idea that deserves its own space.

Kierkegaard defined anxiety as "the dizziness of freedom."

He was not talking about clinical anxiety. He was talking about a specific existential experience: the feeling you get when you realize that your future is genuinely open. That you could do this or that or something else entirely. That there is no predetermined path. That you are radically, terrifyingly free to become almost anything.

Most people experience this and immediately flee from it. They make hasty decisions, follow social scripts, fill the openness with noise and distraction, anything to avoid sitting with the vertigo of real freedom.

Kierkegaard thought this was a mistake. Anxiety is not a malfunction. It is the sign that you are actually confronting your freedom honestly. It is the beginning of genuine selfhood rather than the borrowed selfhood of the crowd.

The person who never feels existential anxiety is not the person who has found peace. They are the person who has never looked honestly at their situation.

Learning to tolerate that anxiety, to sit with it rather than flee from it, is the beginning of actually becoming who you are.

Why Kierkegaard Still Matters

Kierkegaard died thinking he had failed. The city that had mocked him during his lifetime gave him a small funeral and moved on.

Then everything he had described started happening at scale.

The twentieth century took the individual and tried to dissolve them into systems, into ideologies, into masses, into historical forces. And the people who pushed back hardest, Sartre, Camus, Heidegger, Simone de Beauvoir, were all drawing on Kierkegaard's insistence that the individual cannot be reduced, that existence comes before essence, that the choosing self is irreducible and cannot be explained away.

His questions are still the hardest ones.

What does it mean to actually choose your life rather than drift through it? What does it mean to think for yourself rather than think with the crowd? What do you do when you face a demand that no system can resolve for you?

He did not answer these questions. He showed you why they cannot be avoided.

And that is what philosophy is actually for. Not to hand you a set of conclusions. To make it impossible for you to keep sleepwalking past the questions that define your life.

Kierkegaard was very good at that.

He still is.

One Thing Worth Trying

Kierkegaard wrote most of his books as dialogues, arguments, voices talking to each other and to the reader. He wanted philosophy to feel like a living confrontation, not a lecture.

The best way to engage with his ideas is not to read summaries of them. It is to argue with them. To bring them to Socratic AI and push on them. Do you actually agree that the crowd is untruth? Is the leap of faith a genuine philosophical insight or an excuse to believe whatever you want? Are you living at the aesthetic stage and calling it something else?

These are not comfortable questions. Kierkegaard did not write comfortable philosophy.

He wrote the kind that changes things.