Existential Gravity: Relationships and Nietzsche’s Eternal Return in The Unbearable Lightness of Being

by Serena May

The Unbearable Lightness of Being, written by Milan Kundera, expands on the concepts of existential weight and lightness that were originally formulated in Friedrich Nietzsche’s eternal return thought experiment (§341).[i] In this essay, I explore Kundera’s interpretation of existential gravity in order to develop an account of the distinction between existential weight and lightness, and subsequently consider how this applies to the relationships between specific characters within his novel. Nietzsche’s concept of eternal return asks us to imagine discovering that the life we currently live is to be re-lived for eternity: “there will be nothing new in it, but every pain and every joy and every thought and sigh and everything unutterably small or great in your life will have to return to you, all in the same succession and sequence…”[ii] Nietzsche suggests that eternal return would therefore amount to “the greatest weight”, as every decision would involve asking whether you “desire this once more and innumerable times more?”[iii] The life of eternal return can thus be perceived as a never-ending, repetitious cycle which results in substantial existential heaviness. Given that such a life incurs “the greatest weight”, what happens if we suppose, as Kundera does, that the “mad myth” of eternal return is false?[iv]

In contrast to the existential heaviness found in Nietzsche’s thought experiment, Kundera believes that our lives are existentially light, and “unbearably” so.[v] His argument does, however, draw upon the “mad myth” in order to elucidate the concept of existential gravity. Parmenides, a Greek philosopher in the 5th century BCE,[vi] divided the qualities of the world into pairs of opposites: light/darkness, fineness/coarseness, warmth/cold.[vii] Parmenides held the opposite qualities up against his model of contradictories and whichever corresponded to light was the positive quality; whichever corresponded to dark, the negative.[viii]Kundera asks the reader, “Which one is positive, weight or lightness?”[ix] Parmenides thought: lightness is positive, weight negative.[x] Kundera questions Parmenides’s response by asking, “but is the heaviness truly deplorable and lightness splendid?”[xi] Our one and only life is lived in a linear fashion, and for Kundera, “what happens but once might as well not have happened at all.”[xii] Without the circular notion of eternal return, it appears to Kundera that our lives are meaningless. In Ecce Homo, Nietzsche writes, “my formula for greatness in a human being is amor fati” (§10).[xiii] Amor fati, or love of fate, is intertwined with the concept of eternal return. For Nietzsche, a human’s highest state of being is achieved through the complete affirmation of life and, if eternal return were real, he believes we would eventually embrace the concept and its weight by learning to love our fate. Kundera expands on this notion of existential weight in part one of The Unbearable Lightness of Being. He suggests that “the heaviest of burdens is… simultaneously an image of life’s most intense fulfillment. The heavier the burden, the closer our lives come to the earth, the more real and truthful they become.”[xiv]

I argue that Kundera therefore believes that humans long for repetition and a determined fate, as these aspects of life result in a burden of obligation which creates meaning (and thus weight) in their lives. This belief applies to a variety of situations in our lives, however Kundera focuses on relationships to express this idea. The literature reviewing The Unbearable Lightness of Beingagrees that the novel’s characters grapple with the existential weight created by the repetition of long term relationships.[xv]When confronted by the prospect of being in a relationship, some characters find it difficult to determine whether they desire to be existentially heavy or light. If a character is a bachelor or mistress, Kundera describes their life as a straight line with an unknown future causing this character to be light and free. If, on the other hand, a character is in a relationship, their life is heavy, repetitious and meaningfully burdensome. The current literature compares these two situations but ultimately fails to comment on the rapid shift in the existential force that is experienced upon entering or exiting a relationship. I have chosen to use the term “existential vertigo” to describe the existential shift a character undergoes when they transition from existential heaviness to existential lightness too rapidly. To avoid confusion, I should note that my inclusion of the term is with respect to the topic of existential weight, which is separate from Jean-Paul Sartre’s use of the term. Sartre coined the term “existential vertigo” to reference the “nausea” which comes from grasping the utter contingency of all existence on a cosmic level. In this essay, I inaugurate the term to explain the feeling experienced when a drastic change in a person’s life causes a shift in their existential gravity. 

Existential gravity is complex. As Kundera explicitly states, “the lightness/weight opposition is the most mysterious, most ambiguous of all.”[xvi] Despite this ambiguity, one thing is certain – the character’s existential heaviness or lightness is dependent upon the decisions they make in life. Such decision making is incredibly difficult because “we are not granted a second, third, or fourth life in which to compare various decisions.”[xvii] Some of the characters in the novel, such as Tomas, attempt to ease the pressure of decision making by creating metaphors and assigning themselves a fate through their interpretations of motifs and fortuities. 

Tomas, who is confronted with the responsibility of making several life-changing decisions throughout the novel, arguably provides the reader with the clearest contrast between existential lightness and weight. At the beginning of the novel, we discover that Tomas has been living as a bachelor for ten years. Kundera encourages us to interpret this as an absolute absence of burden which causes Tomas to be “lighter than air” with “his movements as free as they are insignificant.”[xviii] Upon meeting Terza, Tomas stands in his courtyard to deliberate on whether he should approach her again. Kundera includes phrases such as, “he feared the responsibility,” to evoke the sense of existential weight involved if Tomas chooses to see Terza again.[xix] Tomas oversimplifies the decision by creating a metaphor about Terza being a child in a bulrush basket that is sent downstream for Tomas to fetch at the riverbank of his bed. Kundera adds, “He couldn’t very well let a basket with a child in it float down a stormy river!”[xx] In the novel, these kinds of metaphors help the characters to create imagery about their decisions. However, Kundera reminds the reader that metaphors are not to be trifled with as, “a single metaphor can give birth to love,”[xxi] and those who fall in love become heavy.

Tomas is pushed towards Terza by way of “six chance happenings,” as if “he had little inclination to go to her on his own.”[xxii]Terza therefore becomes known as “the woman born of six laughable fortuities.”[xxiii] Tomas grapples with the problem of whether his relationship with Terza is an “es muss sein” (it must be) or “Es konnte auch anders sein (it could just as well be otherwise). Tomas regards “es muss sein”  to be the elements of his life that are beyond his control; it is the weighty resolution at one with the voice of Fate. In Tomas’s light life as a bachelor, he does not sleep beside his mistresses. Upon meeting Terza, however, he allows her to pull him down and hold his hand whilst they sleep side by side. It appears that Tomas’s compassion towards Terza creates a longing for the repetition we commonly see in partner relationships. In this sense, Kundera believes that relationships are an expression of our longing for value. However, a consequence of this repetitious cycle is that it limits our freedom and creates existential weight. 

Existential weight is complicated for Tomas. This becomes noticeable when Terza leaves him after seven years of being together. Initially, he appreciates that no one forced him to make a decision as Terza was the person who chose to leave the relationship. He then starts to convince himself that this is how their relationship “had to” end.[xxiv] Upon having this train of thought he begins to evaluate the relationship in retrospect as heavy and tiring, concluding that “she might as well have chained iron balls to his ankles.”[xxv] Tomas, as a single man, therefore becomes existentially light. As Kundera writes, “suddenly his step was much lighter. He soared. He had entered Parmenides’ magic field: he was enjoying the sweet lightness of being.”[xxvi] This satisfaction lasts two days and Tomas quickly finds the lightness unbearable. 

Tomas had been living as an existentially heavy man for seven years, so the sudden shift to lightness would most likely feel like existential vertigo. Again, in response to this situation, we see Tomas utilise motifs to guide him through life’s big decisions. He decides to bear “his fate” and follow the allusion presented in Beethoven’s “es muss sein” (it must be).[xxvii] His longing for repetition, interpretation of motifs, and compassion for Terza cause him to return to her. Again, Kundera makes it clear that the consequence of this decision is weight because “the heavier the burden, the closer our lives come to the earth, the more real and truthful they become.”[xxviii] The evening Tomas returns to Terza he experiences the vertigo of his heavy fall. This evidences the fact that it is difficult for one to gauge whether they want to be existentially light or heavy. In Zurich, Tomas desires to fall from the lightness into the heaviness that is Terza’s arms. However, when he returns to Terza in Prague, this feeling disappears.[xxix]Kundera expresses this existential vertigo by stating, “Tomas felt no compassion. All he felt was the pressure in his stomach and the despair of having returned.”[xxx] As previously mentioned, Nietzsche contends that we can embrace the concept of weight and learn to love our fate. Arguably, we see this in Tomas’s character as he ages. 

Towards the end of the novel, Tomas is in bed once again, observing Tereza who is “lying beside him and holding his hand in her sleep.” In this scene, Kundera writes that Tomas feels “an ineffable love for her.”[xxxi] In making this claim, Kundera seems to agree with Nietzsche. Tomas did eventually learn to embrace his repetitious obligation to Tereza, thus allowing for it to create weight, value and meaning in his life. While we see this outcome for Tomas, however, Kundera acknowledges that the complexity of existential gravity means that not every person longs for a life involving repetition or the concept of Fate. A person can just as easily betray their fate and remain existentially light, as we see in the character of Sabina.

Sabina is an existentially light character living a life of freedom. She escapes weight by betraying the concept of Fate, and her consequence is experiencing the unbearable lightness of being. This betrayal is defined as “breaking ranks and going off into the unknown.”[xxxii] Sabina finds the unknown “magnificent,” as she loathes the concept of Fate and despises the heavy life that her father had lived.[xxxiii] Existentially light people embrace the concept of absolute freedom and act on self-centred impulses. Unlike Tomas, who interprets fortuity as his fate, Sabina does not allow symbols to have any one specific meaning. Her bowler hat, for example, appears in the novel “again and again, each time with a different meaning,” and all the meanings flow through it, “like water through a riverbed.”[xxxiv] Kundera labelled it “Heraclitus’ (You can’t step twice into the same river) riverbed,” because Sabina does not live a circular life of repetition; she lives a life of constant change.[xxxv]

As I have previously established, Tomas allowed Terza to pull him down and hold his hand through their life of repetition and weight – for Sabina to remain existentially light and free, she must therefore never allow this to occur. As Kundera explores, the consequence of having this goal is the creation of a life that involves a chain of betrayals. Kundera writes: “after she betrayed her father, life opened up before her, a long road of betrayals, each one attracting her as vice and victory.”[xxxvi] Her betrayals fill her with excitement and joy, because they open up new paths to new adventures of betrayal, allowing her future to be unknown.[xxxvii] After betraying her husband, she becomes a mistress and does not allow herself to fall into any burdensome relationships. Towards the end of the novel, Sabina is a mistress to a man called Franz. Her experiences during this time allow the reader to acknowledge that a life lived through impulse and betrayal does not make the experience any less unbearable.

The intoxication of lightness gives way to anguish for Sabina. She ponders whether her road of betrayals will ever end.[xxxviii]This feeling of angst is so intense that she longs to “come to the end of the dangerous road of betrayals,”[xxxix] and considers accepting Franz’s heavy hand that is offered to her when he leaves his wife. The desire to fall from her lightness into Franz’s heavy arms creates a feeling of existential vertigo, which is extremely unpleasant for Sabina. A self-centred distaste develops as a result of the vertigo and although Sabina acknowledges that she is being unfair, she abruptly leaves Franz. Sabina is existentially light again, and Kundera further establishes why the lightness is unbearable: after leaving Franz, Sabina feels an “emptiness all around her”.[xl] What has come over her? “Nothing,” Kundera explains. Sabina left a man because “she felt like leaving him.” Franz had not caused her any further difficulties, thus “her drama was a drama not of heaviness but of lightness.”[xli] Kundera queries whether “that emptiness was the goal of all her betrayals?” Sabina therefore experiences not the burden of weight but of emptiness, which is the “unbearable lightness of being.”[xlii] Without fate, repetition and existential weight, Sabina lives her life in a straight line with an unknown future. 

Kundera’s Unbearable Lightness of Being expands on the complexities originally posed in Nietzsche’s eternal return thought experiment. Kundera agrees with Nietzsche, that if eternal return were true, humans would eventually learn to embrace the repetitious cycle of their fate. Kundera additionally claims that because this “mad myth” is false, humans actually long for repetition in their life as the emptiness of existential lightness can feel unbearable and meaningless. In The Unbearable Lightness of Being, the characters—among them Tomas and Sabina—are aware that their decisions influence their feeling of existential gravity. However, they often struggle to determine whether they want to be existentially heavy or light. Further, if they switch between the two opposing states rapidly, they experience what I refer to as existential vertigo”. Tomas’s belief in the notion of fate and his interpretation of symbols causes him to be existentially heavy. His position is contrasted with Sabina, a character who despises fate, symbols and the burden of others. Her reserved nature prefers the freedom that results from an unknown future. Sabina therefore remains existentially light by betraying obligations that are restricting, repetitive or existentially heavy. Kundera establishes that this lifestyle may appear prima facie appealing; however, the reader should be aware that it can create a feeling of emptiness which he calls, “the unbearable lightness of being.” 

Serena is currently in her fifth year of a double degree in Law and Business. For University exchange, she travelled to the United States and studied philosophy at the University of North Carolina Wilmington (UNCW). Her favourite subjects at UNCW were Existentialism and Philosophy of Mind.


[i]  Friedrich Nietzsche, The Gay Science, trans. Walter Kaufmann (New York: Vintage Books, 1974), 273 – 274. 

[ii]  Nietzsche, The Gay Science, 273. 

[iii]  Nietzsche, The Gay Science, 274.

[iv]  Milan Kundera, The Unbearable Lightness of Being, trans. Michael Henry Heim (New York: Harper Perennial, 2009), 1. 

[v]  Kundera, The Unbearable Lightness of Being, 244.

[vi]  John Palmer, “Parmenides,” The Stanford Encyclopedia of Philosophy (Fall 2019 edition), ed. Edward N. Zalta. Online: https://plato.stanford.edu/entries/parmenides/

[vii] Kundera, The Unbearable Lightness of Being, 5.

[viii] Friedrich Nietzsche, Philosophy in the Tragic Age of the Greeks (Die Philosophie im tragischen Zeitalter der Griechen), [1873], trans. Marianne Cowan (Washington, D C: Gateway Editions, 1962), 71.

[ix]  Kundera, The Unbearable Lightness of Being, 5.

[x]  Kundera, The Unbearable Lightness of Being, 5.

[xi]  Kundera, The Unbearable Lightness of Being, 5.

[xii] Kundera, The Unbearable Lightness of Being, 4.

[xiii] Friedrich Nietzsche, Ecce Homo, trans. R. J. Hollingdale (Penguin Classics, 1979). 

[xiv] Kundera, The Unbearable Lightness of Being, 5. 

[xv] Angela Milton, “Irreconcilable Oppositions: ‘Es Muss Sein’ and The Unbearable Lightness of Being.” Electronic Theses and Dissertations 40 (2013), 14. 

[xvi] Kundera, The Unbearable Lightness of Being, 6. 

[xvii] Kundera, The Unbearable Lightness of Being, 222. 

[xviii] Kundera, The Unbearable Lightness of Being, 5.

[xix] Kundera, The Unbearable Lightness of Being, 6. 

[xx] Kundera, The Unbearable Lightness of Being, 10. 

[xxi] Kundera, The Unbearable Lightness of Being, 11. 

[xxii] Kundera, The Unbearable Lightness of Being, 35. 

[xxiii] Kundera, The Unbearable Lightness of Being, 239.

[xxiv] Kundera, The Unbearable Lightness of Being, 29.

[xxv] Kundera, The Unbearable Lightness of Being, 30.  

[xxvi] Kundera, The Unbearable Lightness of Being, 30.  

[xxvii] Kundera, The Unbearable Lightness of Being, 30.

[xxviii] Kundera, The Unbearable Lightness of Being, 5.

[xxix] Kundera, The Unbearable Lightness of Being, 34.

[xxx] Kundera, The Unbearable Lightness of Being, 35. 

[xxxi] Kundera, The Unbearable Lightness of Being, 239.

[xxxii] Kundera, The Unbearable Lightness of Being, 91.

[xxxiii] Kundera, The Unbearable Lightness of Being, 91.

[xxxiv] Kundera, The Unbearable Lightness of Being, 88.

[xxxv] Kundera, The Unbearable Lightness of Being, 88.

[xxxvi] Kundera, The Unbearable Lightness of Being, 98.

[xxxvii] Kundera, The Unbearable Lightness of Being, 122.

[xxxviii] Kundera, The Unbearable Lightness of Being, 98.

[xxxix] Kundera, The Unbearable Lightness of Being, 115.

[xl] Kundera, The Unbearable Lightness of Being, 122.

[xli] Kundera, The Unbearable Lightness of Being, 122.

[xlii] Kundera, The Unbearable Lightness of Being, 122.


Kimbrell, Gregory. “Existential Investigation: The Unbearable Lightness of Being and History.” Chrestomathy: Annual Review of Undergraduate Research at the College of Charleston 1 (2002): 66-82.

Kundera, Milan. The Unbearable Lightness of Being. Edited by Michael Henry Heim. New York: Harper Perennial, 2009. 

McClamrock, Ron. Final Lecture on Sartre. Albany: University of Albany, 1988. Available at: https://www.albany.edu/~ron/papers/sartre.html

Milton, Angela. “Irreconcilable Oppositions: ‘Es Muss Sein’ and The Unbearable Lightness of Being.” Electronic Theses and Dissertations 40 (2013): 14.

Nietzsche, Friedrich. Ecce Homo. Edited by R. J. Hollingdale. Toledo, OH: Penguin Classics, 1979. 

Nietzsche, Friedrich. Philosophy in the Tragic Age of the Greeks (Die Philosophie im tragischen Zeitalter der Griechen). (1873). Translated by Marianne Cowan. Reprint: Washington, DC: Gateway Editions, 1962.  

Nietzsche, Friedrich. The Gay Science. Edited by Walter Kaufmann. New York: Vintage Books, 1974. 

Palmer, John. “Parmenides.” The Stanford Encyclopedia of Philosophy (Fall 2019 edition). Edited by Edward N. Zalta. Online:https://plato.stanford.edu/entries/parmenides/

Twa, Garth. “The Unbearable Lightness of Being novel by Kundera. Encyclopedia Britannica, 2018. Online: https://www.britannica.com/topic/The-Unbearable-Lightness-of-Being-novel-by-Kundera

Featured image ‘Milan Kundera en 1980, escritor y disidente checo’ by Elisa Cabot via Flickr.



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