Existentialism is very hard to define.

It was a very diverse philosophical movement, composed of thinkers that did not always agree. Yet every major existentialist pointed to basic experiences where life stops making sense. Then, in response to these, each one of them rejected despair by affirming the significance of existence.

We can define existential philosophy as a whole with these two core outlooks: existential tension and existential affirmation.

The Diversity and Unity of Existential Philosophy

Existentialism was a very diverse 19th and 20th Century philosophical movement in Europe and beyond:

• Kierkegaard, Nietzsche, Jaspers, Marcel, Heidegger, Sartre, de Beauvoir, Camus, Fanon, amongst others
• Christians, atheists, and agnostics
• German, French, Danish, Algerian, and Caribbean
• professional academics and those disillusioned with the university
• white men, women, and minorities
• (not to mention a whole host of existential psychologists, psychotherapists, and literary figures)

Because existentialism was so diverse, even some scholars have given up trying to clarify its core perspective.

What exactly is existentialism? This is not a question with a straightforward answer. There is a real question about whether there is any philosophical unity governing the thinkers commonly called existentialist.¹

But there is definitely something defining about all existential philosophy. The difficulty lies in saying what that is.

Many try to define existentialism as a whole with Jean-Paul Sartre’s famous definition for his own brand of existentialism: “existence precedes essence.”²

Sartre and his followers did popularized the term existentialism in France after World War II. But most consider Martin Heidegger a key existentialist thinker, and he rejected Sartre’s definition.³ Sartre’s philosophy was only one branch of a larger existential movement in European philosophy in the 19th and 20th Centuries.

To define existentialism in an inclusive way that fits the larger existential movement, we need to stop using Sartre’s definition for the definition of existentialism as a whole.

What unified this larger existential movement was a common affirmation of the significance of existence against the threat of its insignificance. Each existentialist showed a way to resist what the American philosopher, David Schmidtz, has called “the counsel of despair”—the idea that because our lives can appear insignificant, they don’t matter at all.⁴

All existentialists sought to overcome philosophical despair and affirm that existence still matters.

Existential Tension: the Threat of Nihilism

What unified the existentialist perspective was, first of all, existential tension.

This is the mostly implicit, sometimes explicit awareness of the clash between the way life makes sense from one perspective, but then doesn’t from another perspective. Every existentialist thinker tried to provoke thoughtfulness about existence by pointing to this tension.

Since the ancient Greeks, Western philosophy also sought to make people more thoughtful about life, truth, and reality. But whereas traditional philosophy used rationality to align the individual’s opinions with the truth of a rational world, existentialism argued that the world itself does not fit into a rational framework.

Existentialist philosophers raised awareness about this often overlooked tension by presenting experiences where it erupts into a full-blown realization:

• Kierkegaard pointed to the way that the existing individual’s leap of faith does not make sense from an objective, rational standpoint
• Nietzsche’s madman parable showed how anguish over the death of god undermines the complacent rationality of a secular culture that no longer seeks what god traditionally stood for
• Jaspers discussed limit situations (fright, guilt, finality, and suffering) which expose the uncertainty that underpins human existence
• Heidegger’s anxiety (Angst) showed the way Dasein (human existence) encounters a sense of not being at home in the world where it otherwise usually feels at home
• Sartre’s description of Roquentin’s nausea uncovered the ultimate meaninglessness of a tree root (and all things) in a park
• Camus’ feeling of the absurdity of life brought the ultimate pointlessness of repetitive daily tasks into sharp relief
• Beauvoir pointed to the alienation women feel when external gender norms are imposed upon them and stifle their freedom to flourish as individuals
• Fanon showed how suffering racism sabotages the colonized’s attempts to fit into the colonizer’s world

All of these experiences have their roots in what the German-American philosopher, Hannah Arendt, called philosophical shock:

The functional context of the world in which I too am included can always explain and justify why, for example, there are tables or chairs at all. But it will never be able to make me understand why this table is. And it is the existence of this table, quite apart from tables in general, that evokes the philosophical shock.⁵

Existentialists pointed to these experiences to show how individual existence does not fit into the predominant ways of making sense of life. They wanted to shock their audiences into no longer taking existence for granted.

Facing the senselessness of existence head-on, and raising its stakes against this backdrop, existentialists then showed how to affirm life.

Existential Affirmation: Nihilism vs Existentialism

Every existentialist also chose to resist despair by affirming the significance of existence.

Existential affirmation is an outlook that affirms the significance of existence despite its insignificance from a different angle. Through it, existential philosophers affirmed life even when the world seemed to undermine its value and meaningfulness.

In modern philosophy, existentialism is only one of the two most prominent ways to respond to the senselessness of existence. Nihilism is the other: the belief that the ultimate insignificance of human life diminishes or negates its significance in the here and now. Unlike nihilists, existentialists argued that contrasting human existence against the background of its insignificance should not diminish it, but rather increase its significance.

Each existential philosopher encouraged their readers to affirm their own existence and recommit to flourishing before it is too late:

• Kierkegaard affirmed the importance of making the leap of faith as an individual before God even though from an objective point of view this appears absurd
• Nietzsche’s amor fati (love of fate) and eternal recurrence was an affirmation of life despite all its ugliness, horror, and suffering ad infinitum
• Jaspers presented the response to limit situations as an opportunity to affirm one’s existence
• Heidegger said Dasein (human existence) could become authentic when it resolved upon itself as thrown into factical life in the face of coming death
• Sartre encouraged the creation of one’s own meaning by freely choosing for oneself how one will live
• Camus said to rebel against the absurd not by finding a meaning to live for but by finding a passion for the sensuousness of lived existence
• Beauvoir told women to resist any imprisoning gender norms and flourish as individuals
• Fanon incited resistance against racist systems and promoted the construction of new post-colonial societies where the previously colonized could once again find mutual recognition from others

Existential affirmation is not always about the creation of new meaning. Each existentialist affirmed existence in a different way.

Yet unlike nihilists, all existentialists used the backdrop of existence’s apparent senselessness to heighten the stakes of existing and then affirm it in one way or another.

Tension and Affirmation: Existentialism and Absurdism

Understood through tension and affirmation, existentialism is broad enough to include all the branches of the existential philosophical movement:

• Christian and atheistic/agnostic existentialism
• German existentialism and French existentialism
• Heideggerian existentialism and Sartrean existentialism
• Sartrean existentialism and Camus’ absurdism
• white-male existentialism and feminist, post-colonial existentialism

For instance, from this perspective Camus’ absurdism is clearly different from Sartre’s existentialism (which Camus rejected). But Camus’ absurdism is still a branch of the larger existential movement.

These defining outlooks of tension and affirmation are also specific enough to distinguish existentialism from traditional forms of philosophy and philosophical nihilism:

• whereas traditional philosophy tried to make sense of existence by explaining the rationality of the world (through Western metaphysics), existential philosophy pointed out the breakdown of these traditional ways of making sense of the world
• both nihilists and existentialists inherited this breakdown of traditional sources of meaning
• but while nihilists fell into despair and allowed the insignificance of existence to negate its significance, existentialists affirmed the continuing significance of existence against its insignificance

Despite their diversity, all existentialists used the existential tension to impress upon us the need to become more intentional about affirming our existence while we’re still here.

1. Joseph, Reynolds, and Woodward, “Introduction,” in Joseph, Reynolds, and Woodward The Bloomsbury Companion to Existentialism, Bloomsbury, p. 3. ↩︎
2. Sartre, “Existentialism is a Humanism,” in Sartre, Existentialism is a Humanism, Yale University Press, pp. 20–22. ↩︎
3. Heidegger, “Letter on Humanism,” in Heidegger, Pathmarks, Cambridge University Press. ↩︎
4. Schmidtz, “The Meanings of Life,” in Benatar, life, death & meaning, Rowman & Littlefield, p. 100. ↩︎
5. Arendt, “What is Existential Philosophy?,” in Arendt, Essays in Understanding, Schocken Books, p. 165. ↩︎