Do you ever feel like the weight of every decision you make is crushing you, not just for yourself, but for everyone around you? That moment when you realize there’s no manual, no pre-written script for your life, and you have to figure it out alone? Jean-Paul Sartre knew that feeling intimately and expressed it in his Existentialism Is a Humanism.
And in October 1945, standing before a chaotic, overflowing crowd in Paris, he delivered the lecture that would either liberate you or terrify you, maybe both.
Overview
Existentialism Is a Humanism is the transcribed text of a lecture Sartre gave on October 29, 1945, at the Club Maintenant in Paris. It’s his attempt to defend existentialism against critics, Communists who called it bourgeois and contemplative, and Christians who accused it of wallowing in humanity’s darkest corners.
In roughly 70 pages, Sartre lays out his core argument: existence precedes essence. You aren’t born with a fixed nature or purpose. You exist first, then you define yourself through your choices and actions. This means you’re radically free—and radically responsible. Not just for yourself, but for all of humanity.
The lecture was a media sensation, drawing crowds so large that people fainted and chairs were broken. Sartre himself later regretted publishing it, calling it too simplistic. But despite its flaws—or perhaps because of them—it remains the most accessible entry point into Sartre’s philosophy.
Key takeaway: You are condemned to be free. There’s no God, no human nature, no destiny to fall back on. Your life is what you make of it. That’s both terrifying and exhilarating.
Reader recommendation
Existentialism Is a Humanism is perfect for:
- Philosophy beginners who want a clear, non-technical introduction to existentialism
- Anyone struggling with meaninglessness or decision paralysis
- Readers interested in post-WWII French intellectual history
- People who appreciate punchy, provocative arguments over dense academic prose
I do not suggest Existentialism Is a Humanism to:
- Readers seeking a comprehensive or nuanced account of Sartre’s philosophy (this is a simplified lecture, not Being and Nothingness)
- Those who prefer systematic, step-by-step philosophical treatises
- Anyone looking for practical self-help advice—this is philosophy, not a life coaching manual
- Readers who want a balanced view of existentialism that includes Christian perspectives
Table of Contents
1. Introduction
Book Title: Existentialism Is a Humanism (French: L’existentialisme est un humanisme)
Author: Jean-Paul Sartre (1905–1980)
Publication Details: Originally delivered as a lecture on October 29, 1945, in Paris. First published as a book in 1946 by Les Editions Nagel. The English translation by Philip Mairet appeared in 1948. A newer translation by Carol Macomber, including Sartre’s commentary on Camus’s The Stranger, was published by Yale University Press in 2007.
Author’s Background: Sartre was arguably the best-known philosopher of the twentieth century. A graduate of the prestigious École Normale Supérieure, he studied phenomenology in Berlin, where he encountered the works of Husserl and Heidegger.
By 1945, he had already published his philosophical magnum opus, Being and Nothingness (1943), along with the novel Nausea (1938) and the play The Flies (1943). He was a central figure in French intellectual life, and later became a committed political activist, refusing the Nobel Prize in Literature in 1964.
Context of Existentialism Is a Humanism
The book is a transcript of a public lecture—not a carefully crafted philosophical treatise. Sartre delivered it at a moment when existentialism had become a scandal in France. The term was being thrown around in newspapers, associated with nihilism, despair, and moral decay.
Communists accused existentialism of being a “bourgeois philosophy” that encouraged quietism and inaction.
Christians condemned it for emphasizing “what is despicable about humanity” and ignoring innocence and beauty. Sartre’s lecture was his attempt to set the record straight—to explain what existentialism actually meant and why it was, in fact, a humanism.
Purpose of Existentialism Is a Humanism
The central thesis of Existentialism Is a Humanism is that existence precedes essence—meaning you are not born with a predetermined nature or purpose. You exist first, and then you define yourself through your choices and actions.
This makes you radically free, but also radically responsible—not just for yourself, but for all of humanity. Sartre argues that existentialism is not a philosophy of despair but of action and commitment.
It doesn’t trap you in isolation; it forces you to recognize your connection to others and your role in shaping the human condition.
2. Background
To understand the lecture, you need to know what was happening in France in 1945. The country had just emerged from Nazi occupation. Paris was liberated in August 1944. The war in Europe ended in May 1945. People were grappling with the horror of the Holocaust, the shame of collaboration, and the uncertainty of what came next.
Sartre himself had been drafted in 1939, captured by the Germans in 1940, and spent nine months in a prisoner-of-war camp. He knew what it meant to have your world ripped apart. When he returned to Paris, he found an intellectual scene hungry for new ideas. Existentialism, with its focus on individual freedom and responsibility, struck a chord.
But it also provoked fierce backlash. The Communist Party, which had gained enormous prestige through its role in the Resistance, saw existentialism as a threat. They accused it of being individualistic, subjective, and politically useless. Christians, meanwhile, saw it as atheistic and morally corrupt. Sartre was being attacked from both sides. The lecture was his attempt to defend himself—and to clarify what he actually believed.
The venue was the Club Maintenant, a leftist intellectual forum. The lecture was advertised in major newspapers like Combat, Le Monde, and Le Figaro. According to Sartre’s biographer Annie Cohen-Solal, the event was a “cultural event of the year”. The hall was packed beyond capacity. People fainted. Chairs were broken. Sartre had to fight his way through the crowd just to reach the stage. He began speaking an hour late, in an overheated, chaotic room.
The lecture was published the following year and became an instant sensation. It was translated into English in 1948 and has remained the most common introduction to Sartre’s philosophy ever since. Ironically, Sartre later regretted its publication, feeling it oversimplified his ideas. But the genie was out of the bottle.
3. Existentialism Is a Humanism Summary
What “Existence Precedes Essence” Actually Means
Sartre starts by addressing the criticisms leveled against existentialism. He then defines the doctrine in the simplest possible terms.
“What they have in common is simply their belief that existence precedes essence; or, if you prefer, that subjectivity must be our point of departure.”
To explain this, he uses the example of a paper knife. A paper knife is manufactured with a specific purpose in mind. The craftsman knows what it’s for and how to make it. So the essence of the paper knife—its design, purpose, and production method—precedes its existence. The same was traditionally true of humans. In religious philosophy, God created humans with a specific purpose and nature. Your essence came first; your existence was just the execution of that plan.
Sartre flips this completely. For existentialists, there is no God, no pre-existing human nature, no predetermined purpose. You are thrown into the world without a manual. You exist first. Then, through your choices and actions, you create your essence.
“Man first of all exists, encounters himself, surges up in the world—and defines himself afterwards.”
This is the foundational principle of Sartre’s existentialism. It’s also what makes it so unsettling. If there’s no pre-existing nature, then you have no excuses. You can’t blame your genes, your upbringing, or your circumstances. You are what you make of yourself.
Anguish, Abandonment, and Despair
Sartre introduces three key concepts that sound terrifying but are actually meant to be liberating.
Anguish isn’t about existential dread in the abstract. It’s the specific feeling you get when you realize that your choices don’t just affect you—they affect everyone.
“When we say that man chooses himself, not only do we mean that each of us must choose himself, but also that in choosing himself, he is choosing for all men.”
Every choice you make is a vote for what it means to be human. If you choose to be a coward, you’re saying that cowardice is an acceptable way to be human. If you choose to be brave, you’re affirming courage as a universal value. That’s a heavy burden. Sartre calls it anguish.
He gives the example of a military commander who has to send soldiers into battle. He might receive orders from his superiors, but those orders are so broad that he has to interpret them. The lives of his men depend on his interpretation. He feels anguish—but that anguish doesn’t stop him from acting. It’s the condition of his action.
Abandonment means there’s no God, no cosmic safety net, no pre-written script.
“When we speak of ‘abandonment’—one of Heidegger’s favorite expressions—we merely mean to say that God does not exist, and that we must bear the full consequences of that assertion.”
If there’s no God, there are no absolute moral values handed down from on high. You have to create your own values. You have to decide what’s right and wrong, good and evil, meaningful and meaningless. There’s no one to turn to for answers.
Sartre illustrates this with the story of a student who came to him for advice. The student’s father was a collaborator, his brother had been killed in the war, and his mother was living alone and dependent on him. He had two choices: stay with his mother and support her, or join the Free French Forces and fight for his country. Which was the right choice? Sartre told him there was no right choice. He was free to choose, and he had to bear the full responsibility for whatever he decided.
“You are free, so choose; in other words, invent. No general code of ethics can tell you what you ought to do; there are no signs in this world.”
Despair is Sartre’s term for accepting that you can only count on what’s within your control.
“It means that we must limit ourselves to reckoning only with those things that depend on our will, or on the set of probabilities that enable action.”
You can’t count on the future. You can’t count on other people to do the right thing. You can’t count on history to work out in your favor. All you can do is act, here and now, and accept the consequences.
This sounds bleak. But Sartre insists it’s actually optimistic. It means you’re not a puppet. You’re not determined by your circumstances. You have the power to shape your own life.
Responsibility and the “Image of Man”
One of Sartre’s most striking claims is that when you choose for yourself, you choose for all of humanity.
“In fashioning myself, I fashion Man.”
This is where the “humanism” part comes in. Sartre isn’t saying you should be selfish or narcissistic. He’s saying the opposite. Your choices create a model of what it means to be human. If you choose to be honest, you’re affirming honesty as a universal value. If you choose to be cruel, you’re saying cruelty is acceptable.
This means you can’t separate your personal freedom from the freedom of others.
“I cannot set my own freedom as a goal without also setting the freedom of others as a goal.”
Freedom, for Sartre, is not a solitary pursuit. It’s inherently social. You can only be free in a world where others are free. And you can only realize your own freedom by willing the freedom of others.
Bad Faith and Authenticity
Sartre also introduces the concept of “bad faith”—lying to yourself about your freedom.
“Bad faith is obviously a lie because it is a dissimulation of man’s full freedom of commitment.”
Bad faith happens when you pretend you’re not free. You make excuses. You blame your circumstances, your upbringing, your biology. You tell yourself you had no choice. But you always have a choice. Bad faith is the refusal to accept that.
Sartre gives the example of a waiter who is so absorbed in his role as a waiter that he forgets he’s a human being with free will. He’s playing a part, pretending he’s nothing more than his job. That’s bad faith.
Authenticity, by contrast, is accepting your freedom and taking responsibility for your choices. It’s not easy. It’s uncomfortable. But it’s the only way to live a meaningful life.
Existentialism as Humanism
Sartre ends the lecture by explaining what he means by “humanism.”
There’s a traditional kind of humanism that sees humans as the highest value, to be worshipped and celebrated. Sartre rejects that. It leads to a kind of cult of humanity that can easily become fascist.
Instead, he offers a different definition:
“Man is always outside of himself, and it is in projecting and losing himself beyond himself that man is realized; and, on the other hand, it is in pursuing transcendent goals that he is able to exist.”
In other words, you become fully human not by turning inward, but by reaching outward—by committing to projects, by creating meaning, by taking action in the world. That’s the humanism of existentialism.
“We remind man that there is no legislator other than himself and that he must, in his abandoned state, make his own choices.”
4. Existentialism Is a Humanism Analysis
What I Found Compelling
Reading this lecture, I felt a strange mix of terror and liberation. Sartre is telling you that you’re completely free—but that freedom is a burden you can’t escape. There’s no one to blame, no one to save you, no cosmic plan to fall back on. You’re on your own.
But that’s also the beauty of it. If there’s no pre-written script, then you get to write your own. Your life isn’t determined by your genes, your upbringing, or your circumstances. You are what you make of yourself. That’s empowering.
I also appreciated Sartre’s insistence that freedom is social. You can’t be free in isolation. Your freedom depends on the freedom of others. That’s a powerful corrective to the idea that existentialism is just about selfish individualism.
What I Found Problematic
Sartre’s argument is clear and punchy, but it’s also simplistic. As he himself later admitted, the lecture oversimplifies his philosophy. Being and Nothingness is a dense, complex work. This lecture reduces it to a few catchy phrases: “existence precedes essence,” “condemned to be free,” “hell is other people.” Those phrases are memorable, but they don’t capture the full richness of Sartre’s thought.
There’s also a certain arrogance in Sartre’s tone. He dismisses his critics—both Communists and Christians—without really engaging with their arguments. He assumes that anyone who disagrees with him is acting in bad faith. That’s not exactly a recipe for productive dialogue.
And then there’s the question of whether existentialism is actually a humanism. Critics have pointed out that Sartre’s philosophy can be deeply anti-humanist in its implications. If there’s no human nature, no universal values, no objective meaning, then what’s to stop someone from choosing evil? Sartre says you can judge people who act in bad faith, but his criteria for judgment are vague at best.
5. Strengths and Weaknesses
Strengths
- Accessibility: This is by far the most readable introduction to Sartre’s philosophy. He avoids jargon and explains his ideas with vivid examples.
- Clarity: The central thesis—existence precedes essence—is stated clearly and repeated throughout, making it easy to grasp.
- Provocative: Sartre challenges you to take responsibility for your life. It’s uncomfortable, but it’s also empowering.
- Historical significance: The lecture captures a pivotal moment in intellectual history—the birth of existentialism as a cultural phenomenon.
Weaknesses
- Oversimplification: Sartre himself admitted the lecture was too simplistic. It doesn’t do justice to the complexity of his philosophy.
- Dismissive of critics: Sartre doesn’t engage seriously with his Communist and Christian critics. He simply asserts they’re wrong.
- Lacks nuance: The lecture presents existentialism as a unified doctrine, but there are significant differences between Sartre, Heidegger, Jaspers, and other existentialists.
- Ambiguous humanism: It’s not entirely clear what Sartre means by “humanism,” and his definition is controversial.
6. Comparison with Similar Works
Being and Nothingness by Sartre, 1943
This is the philosophical heavyweight. Being and Nothingness is a dense, systematic work of ontology—over 600 pages of technical philosophy. Existentialism Is a Humanism is a simplified, popularized version of the same ideas. If you want the real thing, read Being and Nothingness. If you want an introduction, read the lecture.
The Myth of Sisyphus by Camus, 1942
Camus and Sartre were friends and rivals. Both wrote about the absurd, but they came to different conclusions. Camus argued that we should embrace the absurd and live with passion and defiance. Sartre argued that we should create our own meaning through action and commitment.
Sartre’s commentary on The Stranger, included in this edition, is a fascinating look at their intellectual relationship.
The Ethics of Ambiguity by Simone de Beauvoir, 1947
Beauvoir, Sartre’s lifelong companion, developed her own version of existentialist ethics. She argued that freedom is the foundation of all values, and that we have a moral obligation to create a world where freedom is possible for everyone. It’s a more systematic and nuanced treatment of the ethical implications of existentialism.
7. Conclusion
Who Should Read This Book?
Existentialism Is a Humanism is for anyone who wants a quick, accessible introduction to Sartre’s philosophy. It’s not a substitute for reading Being and Nothingness, but it’s a great starting point. If you’re grappling with questions about meaning, freedom, and responsibility, this lecture will give you a framework for thinking about them.
It’s also for anyone interested in the intellectual history of the twentieth century. The lecture captures a moment when existentialism was the most talked-about philosophy in the world.
But don’t stop here. Read Being and Nothingness. Read Camus. Read Beauvoir. Read the critics. Sartre’s ideas are provocative, but they’re also contested. Engage with them critically. That’s what existentialism is all about.
Final Thought
Sartre’s lecture is a reminder that philosophy doesn’t have to be dry and academic. It can be urgent, personal, and even scandalous. It can challenge you to confront the hardest questions about your life—and give you the tools to answer them.
“Man is nothing other than his own project. He exists only to the extent that he realizes himself, therefore he is nothing more than the sum of his actions, nothing more than his life.”
That’s both terrifying and liberating. You are what you make of yourself. So what are you going to make?
