There is a model of reality in which every action you take, from falling in love with a particular person to reading this essay right now, is dictated by a Rube Goldberg machine of events set into motion by the Big Bang — a classical universe of clockwork determinism, in which there is no room for choice. There is also a model in which every event is the product of randomness and probability fluctuations — a quantum universe, in which chance is God’s other name.

Hovering between these two versions, haunted by the paradox of free will, is our experience of what we call serendipity — the gladsome coincidence of two events, rendered meaningful by the emotional weight of each and the infinitesimal cosmic odds of their co-occurrence.

But these highly improbable gifts of chance are also rendered meaningful by the focus of our attention, by choosing to attend to those particular elements of reality amid the myriad others swarming us at the same time — for how we choose to pay attention renders the world what it is. The Nobel-winning poet Wisława Szymborska captured this enchanting interplay of mind and reality in her wonderful poem “Love at First Sight.” The Nobel-winning physicist Wolfgang Pauli and his unlikely friend Carl Jung named it synchronicity and placed it at the nexus of physics and psyche.

Whatever their cause, in such moments of dazzling coincidence we feel that beyond the seeming reality of this world lies another, sending us signs, hinting at the possibility of the impossible.

That is what Milan Kundera (April 1, 1929–July 11, 2023) explores throughout his 1984 classic The Unbearable Lightness of Being (public library).

Kundera places chance at the center of the love story unfolding between two people who believe they have chosen each other. Teresa — a romantic full of existential longing and Anna Karenina — is working as a waitress in a restaurant. One evening, a man looks up from his book to order a cognac. At that very moment, Beethoven comes on the radio. Long ago a string quartet had come to play in Tereza’s small town and had rendered Beethoven “her image of the world on the other side, the world she yearned for.” She takes it as a sign — Tomas must be the answer to her yearning. She goes on seeking other signs — when he charges the cognac to his room, she realizes his room number is the same as the street number of the house she grew up in. “Tomas appeared to Tereza in the hotel restaurant as chance in the absolute,” Kundera writes as he considers the psychological machinery of how we imbue such coincidences with meaning:

Our day-to-day life is bombarded with fortuities or, to be more precise, with the accidental meetings of people and events we call coincidences. “Co-incidence” means that two events unexpectedly happen at the same time, they meet: Tomas appears in the hotel restaurant at the same time the radio is playing Beethoven. We do not even notice the great majority of such coincidences. If the seat Tomas occupied had been occupied instead by the local butcher, Tereza never would have noticed the radio was playing Beethoven… But her nascent love inflamed her sense of beauty, and she would never forget that music. Whenever she heard it, she would be touched. Everything going on around her at that moment would be haloed by the music and take on its beauty.

In serendipity, we find an organizing principle for meaning amid the randomness that governs the universe of which our own lives are but an echo. It is the music amid the noise of being. Kundera writes:

Human lives… are composed like music. Guided by his* sense of beauty, an individual transforms a fortuitous occurrence… into a motif, which then assumes a permanent place in the composition of the individual’s life… Without realizing it, the individual composes his life according to the laws of beauty even in times of great distress.

It is important, Kundera argues, to be awake to serendipity — for letting coincidences go unnoticed deprives our lives of “a dimension of beauty.” But his very metaphor undermines the case for pure chance as the conductor of our lives: Music, after all, is not the product of chance but of the composer’s deliberate choice in sequencing the notes and silences. Our experience of beauty is the product of the quality of attention we choose to pay an object. Simone de Beauvoir, writing in the same era as Kundera, came closer to the composite truth when she contemplated how chance and choice converge to shape our lives.

Still, Kundera captures an elemental fact: We may choose to love whom we love, but it is chance that first intersects our fates. Coincidences remind us that chance may not be the sole conductor of our lives, but it is what gives life the capacity for surprise, for sudden deviation from the predicted path — those quickenings of the soul that elevate life above mere existence and envelop it in an aura of magic that makes it worth living. He writes:

Chance and chance alone has a message for us. Everything that occurs out of necessity, everything expected, repeated day in and day out, is mute.

[…]

Necessity knows no magic formula — they are all left to chance.

Complement with Iris Murdoch on love and chance and a Borges-lensed meditation on chance, the universe, and what makes us who we are, then revisit Kundera on the central ambivalences of life and love and the key to great storytelling.