The heart became a symbol of love through a surprisingly long chain of events, stretching from ancient Greek philosophy to medieval French poetry to the biology happening inside your chest right now. No single moment created the connection. Instead, philosophers, poets, artists, and your own nervous system all reinforced the same idea over thousands of years: that the heart is where love lives.
Ancient Philosophers Put Emotion in the Heart
Long before anyone drew a heart on a Valentine’s card, Aristotle made the case that the heart was the center of all thought, emotion, and spiritual life. Writing in the 4th century BC, he argued that the heart connected to every part of the body through blood vessels, making it the natural seat of feeling and intelligence. The brain, in his view, existed mainly to cool the heart down when it got too “hot-blooded” and started to “bubble up.” This sounds strange today, but Aristotle was the most influential thinker of his era, and his heart-centered view of human experience shaped Western thought for centuries.
Not everyone agreed. The Roman physician Galen, working in the 2nd century AD, split the difference. Drawing on Plato’s earlier philosophy, he divided the soul into three parts and assigned each one to a different organ. Rational thought belonged to the brain. Appetite and desire belonged to the liver. But the “spirited soul,” the part responsible for courage, passion, and emotional intensity, stayed in the heart. Even when thinkers tried to dethrone the heart as the body’s command center, they still couldn’t strip it of its emotional role. That middle ground stuck. The heart kept its association with feeling even as the brain gradually claimed thinking.
A Plant, a Coin, and a Possible Origin
One popular theory about the heart shape itself traces back to a now-extinct plant called silphium, a species of giant fennel that grew along the coast of North Africa. The ancient Greeks and Romans at the colony of Cyrene in Libya prized it for everything from cough remedies to cooking. Its most famous use, though, was as a contraceptive. Women would grind up its heart-shaped leaves and ingest them as an early form of birth control.
The Romans were so obsessed with silphium that they stamped silver coins with the plant’s heart-shaped seedpod on one side and the blooming plant on the other. Whether silphium actually worked as contraception is debatable (probably an ancient urban myth), but the visual link is hard to ignore: a heart-shaped seed associated with sex and romance, stamped into currency and circulated across an empire. It’s one plausible thread in the story of how a particular shape became loaded with romantic meaning.
Medieval Artists Drew Love as a Heart
The heart icon as we recognize it didn’t appear in art until the Middle Ages, and its first known romantic use came from a 13th-century French manuscript called the Roman de la Poire (Romance of the Pear). In one illustration, a kneeling figure named Douz Regart delivers a lover’s heart to a lady as proof of his desire. Art historian Pierre Vinken called this “the first illustration of a heart outside the anatomical literature.” The object in the image looks nothing like a modern heart emoji, though. It resembles a pinecone or a pear, with the narrow end pointing upward, consistent with how the 2nd-century physician Galen had described the heart’s physical shape.
Over the next two centuries, the shape slowly transformed. Giotto painted a pear-like heart in his 1305 fresco of Charity in Padua’s Scrovegni Chapel. By the 15th century, the symmetrical form we know today, two rounded lobes at the top and a point at the bottom, had taken hold. No one knows exactly when or why the shape flipped and became stylized this way. But once it did, science couldn’t shake it. Even as anatomists produced accurate drawings of the real organ, the popular symbol remained stubbornly bi-lobed and pointed. People preferred the icon to the anatomy.
Why Love Actually Feels Like It’s in Your Chest
The symbol endures partly because love genuinely registers as a physical sensation in your chest. When you’re attracted to someone, your brain releases a hormone-like substance called phenylethylamine that triggers a cascade of stress and reward chemicals. Norepinephrine kicks in, raising your heart rate and blood pressure. Dopamine floods your reward circuits. Cortisol, the stress hormone, surges. The result is that fluttery, tight, slightly panicked feeling centered right behind your sternum. Your heart is literally beating harder and faster, and your body interprets that as emotion.
The connection goes deeper than just heart rate, though. Your heart contains roughly 40,000 sensory nerve cells called neurites that send signals up through the vagus nerve and spinal cord to emotional processing centers in the brain, including the amygdala and the cerebral cortex. These signals help regulate mood and even influence decision-making. When your heart’s rhythm changes in response to an emotional moment, those nerve cells report back to the brain, creating a feedback loop. You feel something emotionally, your heart responds physically, and then your heart’s response amplifies the emotion. The chest is not just a passive bystander in love. It’s an active participant.
Broken Heart Syndrome Is Real
Perhaps the most striking proof that the heart and love are physically connected is a condition called takotsubo cardiomyopathy, commonly known as broken heart syndrome. Triggered by extreme emotional stress (grief, shock, heartbreak), it causes the left ventricle of the heart to temporarily balloon outward and stop contracting normally. On imaging, the distorted heart resembles a Japanese octopus trap, which is where the name “takotsubo” comes from.
The symptoms mimic a heart attack: chest pain, shortness of breath, abnormal heart rhythms, and elevated cardiac enzymes in the blood. But when doctors look at the coronary arteries, there’s no blockage. The damage comes from a flood of stress hormones. Levels of adrenaline, norepinephrine, and dopamine spike to two to three times their normal concentration, overwhelming the heart’s receptors and temporarily paralyzing parts of the muscle. The condition is reversible in most cases, but it’s a vivid, clinical demonstration that intense emotion can physically reshape the heart.
How Symbol Became Universal
The heart earned its status as the symbol of love because every layer of human culture kept reinforcing the same association. Greek philosophers said the heart was where emotions lived. Roman coins linked a heart-shaped seed to romance. Medieval poets illustrated love as a heart passed between lovers. Renaissance artists refined the shape into something clean and instantly recognizable. And underneath all of that cultural work, biology kept confirming what people already felt: that love shows up in your chest, changes your heartbeat, and in extreme cases, can physically alter the organ itself.
By the time printing presses, greeting cards, and eventually digital communication needed a universal shorthand for love, the heart had thousands of years of philosophical, artistic, and physiological momentum behind it. No other organ came close.