The novel gets a bit confusing right around the start of the final section, Part 7. Why? Because Part 6 felt like the ending. We wrapped up some major thematic issues, we followed all our characters to their death (or, in Sabina's, foresaw her death), and we topped it all off with a nice, short, concluding chapter (Part 6, Chapter 29). We were ready to close our books until we realized, hey, there's another 50 pages to go. So what gives? Let's take a closer look at what Kundera accomplishes in Part 7. Then maybe we can figure out what those final fifty pages are doing.
Part 7 brings home the novel's discussion of the movement of time. By now, Kundera has firmly established his own viewpoint in opposition to Nietzsche's. Nietzsche offered the idea of eternal return, in which time moves circularly and that events were repeated ad infinitum. Kundera disagrees and claims that time is linear, that our lives happen only once. Interestingly, we do get to look at one character – up close in Chapter 7 – for whom time indeed is circular: Karenin.
The narrator previously hinted at Karenin's importance in a discussion of time, early in the novel. In Part 2 the narrator says:
Dog time cannot be plotted along a straight line," he explains; "it does not move on and on, from one thing to the next. It moves in a circle like the hands of a clock, which-they, too, unwilling to dash madly ahead-turn round and round the face, day in and day out following the same path. (2.27.1)
But it is not until Part 7 that the narrator discusses the importance of something like dog time to the novel's human characters.
In this final section of the novel, the narrator delves into a discussion of the word "idyll" in relation to Tereza and Tomas's life in the countryside and the Paradise of man before the Biblical Fall. He claims that life in the countryside, with its routine and predictability, is an attempt to mimic life in the Garden of Eden: "Life in Paradise was not like following a straight line to the unknown; it was not an adventure. It moved in a circle among known objects. Its monotony bred happiness" (7.4.3). In other words, in the Garden of Eden, man experienced time the way animals experience time – as a circle. As the narrator says explicitly, "Adam was like Karenin" (7.4.4).
Except, because Adam was like Karenin, Adam wasn't fully human. To be human is to experience time linearly. (Remember Kundera's central thesis of the novel, as established in the opening two chapters, is that we experience time linearly.) This is his rejection of eternal return. For man, life happens only once. Therefore, he says, "the longing for Paradise" (i.e., the longing to experience time in a circle) "is man's longing not to be man" (7.4.5).
Which brings us to one of the most important passages in Part 7:
If Karenin had been a person instead of a dog, he would surely have long since said to Tereza, "Look, I'm sick and tired of carrying that roll in my mouth every day. Can't you come up with something different?" And therein lies the whole of man's plight. Human time does not turn in a circle; it runs ahead in a straight line. That is why man cannot be happy: happiness is the longing for repetition. (7.4.13)
Happiness lies in repetition; repetition is at the heart of eternal return; eternal return is what gives lives weight. Because humans don't experience things circularly, events are not repeated for us, which means they don't gather weight, which means they are light – unbearably so. Hence…the unbearable lightness of being.
And now we start to see why these last fifty pages are important. Kundera began his novel with a premise stated right there in his title: life is light, and is unbearable because of it. And it's not until the end of the novel that he concludes his arguments as to why that is.
You know, after 300 pages of intense philosophy, you begin to expect a bigger bang at the final scene of The Unbearable Lightness of Being. At the very least, you certainly don't expect to end with the main characters walking in a hotel room one night after dancing, ready to go to bed.
But remember that we've already covered the typical "ending" stuff in Chapter 6 – we already know how Tomas and Tereza will die, what effect this has on those who love them (like Simon and Sabina), and what remains of them after their death. So we don't need a wrap up conclusion here. As far as the narrative or its plotline is concerned, that's already been addressed.
So what does the final scene do if not wrap up the plot? Plenty. Let's take a closer look at that last paragraph:
Tomas turned the key and switched on the ceiling light. Tereza saw two beds pushed together, one of them flanked by a bedside table and lamp. Up out of the lampshade, startled by the overhead light, flew a large nocturnal butterfly that began circling the room. The strains of the piano and violin rose up weakly from below.
Two things jump out as us here. The first is the sound of the piano and violin, which resonate with the novel's idea of the human life as a musical composition. Read all about it in "Symbolism, Imagery, Allegory." The second is, of course, the large butterfly that flies around the ceiling.
To begin, the butterfly might remind you of the series of fortuities or lucky events that catalyzed Tereza and Tomas's initial meeting. The narrator said that the fortuities "fluttered down […] like birds to Francis of Assisi's shoulders," and in fact repeated this phrasing several times (another example of the strategic iteration we discuss in "Writing Style") (2.9.7). The butterfly here is a beautiful fortuity in itself.
And that's not all. Backtrack about a dozen pages to Tereza's dream a few days earlier, as detailed in Part 7, Chapter 6. In her dream, Tomas is turned into a rabbit that she takes in her arms and carries to house where she lived in as a child. There, she is first greeted by her great-grandfather and great-grandmother, and then walks upstairs to her childhood room:
It had a bed, a table, and a chair. The table had a lamp on it, a lamp that had never stopped burning in anticipation of her return, and on the lamp perched a butterfly with two large eyes painted on its widespread wings. Tereza knew she was at her goal. She lay down on the bed and pressed the rabbit to her face. (7.6.16)
This is such an interesting dream because it is rooted in the hope for eternal return. Tereza finds a home with her great-grandparents, who have recurred in the present time. Tereza herself has "returned" to the place of her childhood, which means that in this dream, time has moved cyclically for her. When the butterfly crops up again in the final scene, it is a recurrence of this moment here, much the way that Sabina's hat recurs for her and becomes a motif in the musical composition of her life. Remember Kundera's earlier claim that human lives are composed according to the laws of beauty? (Definitely check out "Symbolism, Imagery, Allegory" for more on this idea.) There are symbols, motifs, recurring images, and symmetries to be found in our lives if we have a keen enough aesthetic sense to recognize these elements of beauty. This butterfly, in the final moments of the novel, is one such element of beauty.