Just as the illustrative heart in art appeared during the Middle Ages, so did its symbolic use in the literature of the time. In his autobiographical Vita Nuova (1294), Dante Alighieri wrote of his love for Beatrice: “I felt in my heart a loving spirit that was sleeping; and then I saw Love coming from far away so glad, I could just recognise.” Dante goes on to dream that Beatrice eats his heart.

In Giovanni Boccaccio’s narrative poem Amorosa Visione (1342), the theme of the heart as a book, its walls to be written on, shifts from containing words from God to words from one’s love:

As I stood there I seemed to see
this gentle woman come toward me
and open me in my breast, then write there
inside my heart, placed to suffer,
her beautiful name with letters of gold
so that is could never leave from there.  

In Boccaccio’s collection of one hundred tales titled Decameron (1350), two stories represent the heart, perhaps too vividly, as true love. In the first tale of day four, Tancredi, the Prince of Salerno, is incestuously attracted to his daughter Ghismonda. Out of jealousy, he slays his daughter’s lover Guiscardo and sends her his heart in a golden cup. Ghismonda raises her lover’s heart to her lips and kisses it. “I know that his soul still resides here in you and is looking at the place where he and I knew happiness.” She thanks the servants for her father’s priceless gift to her. She adds her tears and poison to the cup, which she drinks. “O beloved heart, all I was to do for you I have now done, and nothing remains but to make my soul join with that one which you have held so dearly.” She then crawls into bed clutching her lover’s heart to await death.

In the ninth tale of day four, the knight Guillaume de Roussillon murders his wife’s lover, his friend who is also a knight. Roussillon cuts out his heart and has it sent to his cook, instructing him to prepare a special dish with this “boar’s heart.” When the cooked heart arrives at the table, Roussillon has no appetite. He gives the special dish to his lady, who eats up every delicious morsel. Roussillon asks, “Madam, how liked you this dish?” Why yes, she replies, very much so. Roussillon then tells her that he cut the heart out of her lover with his own hands. Instead of gagging and vomiting, the lady declares that she’ll never taste another piece of food since she has eaten the most perfect thing in the world. She then steps to the window and jumps to her death.

Shakespeare famously wrote about the symbolic heart in his verse. In his Sonnet 141 (1609), he writes:

But my five wits nor my five senses can
Dissuade one foolish heart from serving thee.
Who leaves unswayed the likeness of a man
Thy proud heart’s slave and vassal wretch to be  

In Much Ado About Nothing (1623), after Benedick blurts out that he loves her, Beatrice finally admits, “I love you with so much of my heart that none is left to protest.”

And when too proud King Lear (1606) asks his three daughters to profess their love to him to receive parts of his kingdom, unlike her two older deceitful sisters Cordelia (cor as in heart) cannot express her love to him: “I cannot heave my heart into my mouth.” He does not understand that she cannot express how great her love is for him, and he angrily disinherits her – a Shakespearian tragedy.

The heart as the path to God appears in Sir Arthur Conan Doyle’s The Stark Munro Letters written in 1895. Dr Munro states in an argument with the High Church curate of the parish, “I carry my own church about under my own hat, said I. Bricks and mortar won’t make a staircase to heaven. I believe with your Master that the human heart is the best temple.”

The surest way to rid the world of a vampire can be found in Bram Stoker’s Dracula written in 1897. Professor Abraham Van Helsing writes to Doctor John Seward that the latter must “Take the papers that are with this, the diaries of Harker and the rest, and read them, and then find this great UnDead, and cut off his head and burn his heart or drive a stake through it, so that the world may rest from him.”

The heart has ever since been and continues to be used as a vehicle in the literary arts to represent romantic love, familial love, love of God, of what is good in us. Here are some recent examples in modern literature. In James Joyce’s A Portrait of the Artist as a Young Man (1916), as a teenager Stephen first experiences the desire of the heart: “His heart danced upon her movements like a cork upon a tide.” When Sabina in Milan Kundera’s The Unbearable Lightness of Being (1984) is observing the American senator watching his children run and play, she thinks, “When the heart speaks, the mind finds it indecent to object.” In renouncing logic, she is saying that what our feelings in our hearts tell us are truer than what our thoughts do.

Wishing that his heart was empty of feelings, trying to disconnect himself from his humanity, the father in Cormac McCarthy’s The Road (2006) thinks to himself, “If only my heart were stone.” In Delia Owens’s Where the Crawdads Sing (2018), some months after her mother left her, Kya’s pain in her heart from loneliness and loss begins to dull: “Until at last, at some unclaimed moment, the heart-pain seeped away like water into sand. Still there, but deep.” After Katherine tells him she always loved him, Almásy confesses his tortured heart to Katherine in Michael Ondaatje’s The English Patient (1992). He must leave her mortally wounded in the cave but promises to come back for her body: “Every night I cut out my heart. But in the morning, it was full again.”

Excerpted with permission from The Curious History of the Heart: A Cultural and Scientific Journey, Vincent M Figueredo, Bloomsbury.