It pumps our blood through a network thousands of miles long, every day. It’s where we feel our most powerful emotions. Its simple, symmetrical symbol is recognized the world over. Love your heart this Valentine’s Day.

February is the month of hearts–a flood of pink and red–on cards, cakes, and even underwear. Hearts appear this month as pendants, balloons, erasers, and candy. On Valentine’s Day, we give all kinds of hearts away to show that we have surrendered our own. For kids a heart-shaped Valentine says, “I like you.” For adults, it represents romantic love or, at least, romantic interest.

But the red heart symbol does not fade away after February 14. In Western societies, we encounter it year-round as a symbol for the entire spectrum of love–from ardent passion to simple fondness. When the graphic designer Milton Glaser created the “I  NY” logo in 1976 to boost tourism in the Big Apple, his interpretation spoke more of pride and dedication to a place. The logo has since been resurrected post-9/11, this time infused with patriotic fervor. But beyond that, the heart symbol is fully integrated into our cultural vocabulary as shorthand for affection. Sports fans, students, and pet owners use it to advertise their loyalties.

But the real heart signifies much more. It has been described as the core of a human being, as the “sun” around which other parts of the human system re-volve. In various cultures, it is believed to be the abode of many emotions, holding not only the various forms of love (passion, empathy, and unconditional love) but also anger, sadness, goodness, truthfulness, and courage. For centuries, Christians considered the heart to be the seat of the soul. Stories, myths, and fairy tales often take the heart for the entire person. Perhaps because its beating confirms that we are alive, the heart stands for life itself. An organ that is so central to our existence deserves attention and care–and not just on Valentine’s Day.

Next to the cross, the heart is the most widely recognized symbol in the world. And though it has appeared in Western cultures for centuries, its origins are unclear. It certainly looks very little like a real heart, which is asymmetrical, but a lot like another part of human anatomy. Gloria Steinem, in fact, has proposed that because of the heart symbol’s symmetry it resembles the vulva, and is a residual female genital symbol. According to Steinem, centuries of male dominance have reduced it from a sign of life-giving power to a mere emblem of romance.

But contemporary German cardiologist Armin Dietz says the heart image has nothing to do with any part of the human body, but instead gradually evolved from ancient depictions of fig and ivy leaves. These leaves have been found on vessels and frescoes that date back thousands of years. On Greek pillars and Roman gravestones, Dietz says, leaves represented physical love as well as the eternal love that withstands death.

Sometime in the Middle Ages, the green leaf morphed into the red heart. Taking their inspiration from antiquity and Roman times, monastic illustrators often painted Trees of Life with heart-shaped leaves; in some paintings from the 12th and 13th centuries, ivy leaves adorn love scenes. Eventually, these shapes were colored red, perhaps because warm blood signified good luck, health, and love. In sacred art, angels and saints hold their hearts in their hand, offering them to God as a symbol of everlasting, self-sacrificing love. During medieval times, the red heart also appeared on playing cards, and these, packed in the bags of soldiers, merchants, and other travelers, helped to disseminate the red symbol across the old world. In western Europe, medieval medical practitioners and anatomists used the heart symbol in their texts to depict the organ. By the time Da Vinci depicted an anatomically correct heart, around 1500, the curvy heart shape was already firmly established as the organ’s symbolic representation.

With its simple mirrored curve–pleasing to the eye in its roundness up top and perfect pointy meeting at bottom–the plain shape of the heart symbol belies the complexity of the physical organ, which is nothing short of miraculous. About the size of a fist, a real heart is located under the rib cage, to the left of the sternum (breastbone), between the lungs. It is a four-chambered muscle and is divided into the left and right side by a wall of muscle tissue (the septum). Both sides are further divided into two top chambers called the atria, which receive blood from the veins, and two bottom chambers called ventricles, which pump blood into the arteries. A human body’s vast system of blood vessels–the arteries, veins, and capillaries that make up the circulatory system–is more than 60,000 miles long. That’s long enough to wrap around the Earth more than twice.

As blood leaves each chamber of the heart it passes through a valve, and every time the valves close they produce a sound: the heartbeat. When the body is at rest, a healthy heart beats 50 to 80 times a minute, about 100,000 times per day. Exercise, emotions, fever, and some medications can cause the heart to beat faster, sometimes to well over 100 beats per minute.

A healthy heart continuously pumps oxygen and nutrient-rich blood throughout the body, moving five or six quarts of blood each minute as it expands and contracts (this is the equivalent of about 2,000 gallons per day). It does not rest, ever.

This sophisticated pumping station has its own electrical system, which provides power for continuous contracting and relaxing. An EKG measures these electrical impulses and charts whether they travel evenly throughout the heart. A sad and broken heart, it turns out, has its own melancholy rhythm. In their book A General Theory of Love (Random House, 2000) San Francisco State psychiatry professors Lewis, Amini, and Lannon explain that despair has a “physiologic signature”–the heart rate is low and an electrocardiogram will show “abnormal, serrated beats.”

Tucked deep inside our body, our heart makes itself known to us with its sound. So perhaps it’s no wonder it’s become associated with the presence of life itself–and its silence with death. The curious practice of “heart burials,” fashionable since early times among European royalty and church dignitaries, was meant to demonstrate everlasting life and power. While heart burials probably started for logistical reasons–during the Crusades it was impossible to transport bodies over long distances, so only the hearts of Crusaders killed in battle were brought home for burial–the Bourbon dynasty in France and the Habsburgs of Austria practiced separate heart burial long after the Crusades. In fact, the last Austrian empress, Zita, had her heart buried separately as recently as 1989.

But the brain would eventually take the throne as the organ of primary importance. Early Christians may have accorded the heart a superior role, as the home of the soul, and Renaissance physicians may have defined it as the sun in the microcosmos of the human body, but its reign would not last forever.

In the 18th century, the heart toppled from its pedestal. It was the dawn of what we call “modern science” and of a new conception of the human body’s inner workings. Academics and scientists scorned so-called mystical elements, and a new dualistic worldview divided our beings into mind and body, thought and feeling, matter and spirit. In the 17th century, French mathematician Blaise Pascal captured this duality when he wrote that “the heart has its reasons whereof Reason knows nothing.” Cartesian physicians further demoted the heart when they stripped it of all emotional attributes and instead saw it as the miraculous, restless spring in the clockwork mechanism of the human body. During the Industrial Revolution, physicians built on this notion, using the metaphor of the machine to characterize organs according to their specific functions: the heart was the pump, the kidney the filter, and the brain the thinker or as we would say today, the computer.

This approach did not exist outside the Western world. Jen Resnick, head instructor at the Oakland-based Hand to Hand Kajukenbo Self Defense Center and a practitioner of Traditional Chinese Medicine, explains that the Chinese character for heart transcends Western dualism–it also signifies “mind.” In Chinese thought, she explains, all things are connected with each other and are constantly in motion. To look at a particular organ as static and in isolation (as Europeans did when they studied corpses) inevitably yields inadequate information. In Chinese medicine, explains Resnick, the heart is one of the five elements that make up each individual body as well as the world at large. It is associated with the element of fire and the color red, and although it is not the only organ linked with emotions, it is the place where spirit resides. Acupuncturists treat the heart in cases of depression or insomnia as well as any time an individual’s spirit is disturbed, as in cases of mental illness.

Interestingly, in East Indian tradition, the heart is the integrator of mind and body, spirit and matter. When the heart chakra is closed, our breathing is shallow and our metabolism and physical energy slowed. We withdraw, and become a closed system. When the heart chakra is too open, there is the tendency to give all our time and energy away.

But in the West, over time, the brain has taken over as the primary control center. Psychiatrists Lewis, Amini, and Lannon summarize biological and psychological research which shows that it is the limbic brain, which drapes itself around the reptilian brain and is itself surrounded by the neocortical brain, not the heart, that governs our emotional lives and ability to love. Emotions can be felt in the heart as a pounding or a constriction, but they originate in this part of the brain, which distinguishes us mammals from reptiles.

Biologically, then, there is no hard evidence that the heart is the home of feelings. True, it can maintain cells and preserve the body, as in the case of a person who is “brain dead.” And once the heart stops beating, the body begins to crumble. But as Dr. Ralph Brindis, cardiovascular specialist at Kaiser in Oakland, points out, “a functioning heart and respiratory system do not make a person.” According to him, “the brain is our core, not the heart.”

Brindis does acknowledge a link between mental and cardiovascular health. There is, for example, a relationship between depression and coronary artery disease. It has long been known, he explains, that heart conditions can lead to depression because they limit people’s activities and require lifestyle changes. Surprisingly, the inverse is true, too. “Depression itself has been implicated in playing a role in causing heart attacks,” Brindis says.

Although Brindis points out that “we are still in the infancy of understanding the relationship between emotional health and our actual physical health,” many therapists and healthcare practitioners believe that aligning the mind with the heart is a key to greater well-being. Indeed, this is a core concept in some forms of bodywork. Rosen Method Bodywork, which is taught at the Berkeley-based Rosen Institute, aims to heal the split between thoughts and feelings. Even if emotions are located in the limbic brain, people generally have difficulty accessing their feelings through the mind. It can be much more effective, say Rosen Method practitioners, to work through the heart.

Longtime Rosen Method teacher and practitioner Odile Atthalin says she has often seen a simple touch to a client’s heart area begin to unlock emotional awareness. From her own experience, she knows the benefits of this approach.

“When I was seven, I lost a baby brother,” Atthalin says. “Because my mother’s pain was so overwhelming, my own grief and love were ignored and got buried deep inside my small armored chest. It was only 30 years later that I could allow my chest to open again and then I was flooded with those feelings of loss and love that could finally be fully felt, resolved, and released, and that I could feel myself as ‘full of love.’

“Some version of this happens to all of us,” she continues. “We need to go into our heart and retrieve our ability to love.”

Pursuing a similar thread, researcher and consultant Doc Childre founded the HeartMath Institute in Boulder 15 years ago. HeartMath researches the influence the heart has on brain activity, emotional perception, and experience. The institute’s work hinges on the concept of “heart intelligence,” or the awareness a person experiences only when their mind and emotions are brought “into alignment with the heart.”

The Story of the Beautiful Heart In a small town, a contest is being prepared, a contest for the most beautiful heart. Banners hang from buildings, calling all the inhabitants to come and show their hearts, so that the most beautiful one may be chosen. On the designated evening, hundreds of people crowd into the theater and many of them line up on the stage to compete for the prize. A young woman is first in line. She takes her delicate pink heart from a jeweled box for all to admire. Ooh! Ahh! The audience appreciates this unblemished specimen. A man removes a light blue heart covered with interesting small dents from a silver container–it is made of ice. A boy unwraps a perfect red heart, whole and strong. A woman takes hers from a silken sack–it is the color of mother of pearl and flutters with every beat. Every person presenting his or her beautiful heart smiles proudly as the audience claps and cheers. Finally, an old woman comes up on stage. The heart she takes from her pocket is faded and torn; unsightly blotches cover most of its soft, iridescent red surface. The audience boos and hisses, protesting that her ugly heart has no place in this contest. But the woman puts one finger to her lips to silence the crowd. “Let me tell you the story of my heart,” she says. “See this rip? It happened when my first beloved left me. This glittering patch appeared when my baby was born. And this slash? It never healed when my firstborn died in winter cold. That scar has been there since my father was lost at sea. The ruby-red sparkles appear when I do what I love. This black mark developed when my mother passed, and that one when my best friend went mad.” On and on the woman went, describing the origins of the blemishes, the wounds, and the beauty marks upon her heart. When she was finished, she stroked it tenderly. “This heart has loved,” she whispered. “Isn’t it beautiful?” Heard years ago at a memorial celebration in Bishop, California. –C.S.

After studying heart rate variability (beat-to-beat changes in the heart rate) as a measure of how a person’s life is balanced emotionally and mentally, Childre and HeartMath Executive Vice President Howard Martin found that negative emotions–anger and frustration, for example–increase disorder in the heart’s rhythms, decreasing the overall health of the body.

Positive emotions, on the other hand, like love, appreciation, care, and compassion, increase coherence in heart rhythms, improving balance in the nervous system. The gist: good feelings are good for you. As the heart communicates with the brain, positive emotions actually increase learning, performance, and longevity, according to HeartMath research.

A large hospital in Orange County, for example, conducted its own internal study on 75 patients with severe heart conditions. Taught how to use one of HeartMath’s products–an antianxiety software program and heart rhythm monitor–71 of the patients reported after three months a substantial improvement in physical and emotional health. Fourteen were able to stop taking some medications altogether, and the study coordinator described the results as “significant, life-changing, and priceless.”

Poets and mystics who have always believed that blending thought and feeling is the key to wisdom, will shrug at this science. They might point to commonly used figures of speech as evidence that the heart never really relinquished its primary role.

Unlike the mind, the heart does not know duplicity and it cannot be fooled. We “cross our hearts” when we want to emphasize our sincerity. We have a “heart to heart talk” when we want to be truthful. When we “speak from the heart,” we are honest. When we “listen with the heart,” we suspend our judgment. We associate the heart with positive values, such as courage and bravery (“faint of heart,” “brave heart”). We connect it to vitality (“hearty”) and to memory (“learning by heart”). Last but not least, the heart is linked with emotional accessibility (“softhearted” or, its contrary, “heart of stone”).

Our language also reminds us that our emotional heart is active and has a life of its own. It can dance, burst, awaken, bleed, tremble, open, and close. We can lose heart, give it away, and wear it on our sleeve. We can even leave it behind, as Tony Bennett did in San Francisco. It’s been said that to watch your own child go through life’s struggles can feel like your heart is traveling–vulnerable, yet determined–outside your body.

This, then, is the other side of the heart: Just as it is the seat of love, it is also the place we associate with profound sadness and deep pain. Few things hurt as much as a broken heart, which we tend to think of in the context of romance. Psychotherapists, however, proceed from the assumption that for most of us, the first heartbreak actually occurs early in our lives, when we may be hurt, neglected, rejected, or even abused by our parents or caregivers. When we feel intense emotional pain as adults, it is because our heartbreaks from the past are triggered.

Berkeley-based psychotherapist Jane Steinberg refers to protective patterns we use to buffer against the risk of heartbreak. “Every time a person falls in love, they believe that this time, they will keep their hearts open,” she says. “But they inevitably revert to established patterns of protecting the heart with their new partners.” These unconscious heart defenses constructed in childhood do not ultimately protect us, says Steinberg.

“Tragically,” she explains, “these emotional defenses actually create loss instead of preventing it.”

The heart may be the size of a fist, but really, it is infinite. Next time you spot the little red symbol, go ahead and think of your beloved, of your favorite past-time, or of civic pride. But also consider your own physical heart. Place your hand over your chest and feel the regular beating, like a drum. Marvel at the heart’s complex functioning. Appreciate it for the incredibly hard work it is doing every second. Strengthen it by getting enough exercise, eliminating fatty foods from your diet, and refraining from smoking. But don’t stop there.

Pay attention to your emotional heart. Nourish it by doing things you enjoy and spending time with people–or creatures–that make you feel good. Finally, don’t forget your spiritual heart–that amazingly spacious place that holds joy and love. Even when the mind feels crushed by fear and you are doubled over with emotional pain, your heart holds the Hallelujah. And that is infinitely bigger than the heart-shaped proclamations of affection that thrill us on Valentine’s Day. l

Christine Schoefer is a freelance writer based in Berkeley, a city she sees with new eyes after returning from a three-year sojourn in the German countryside.