Islam has become associated with al-Qaeda and the constant threat of terrorist attack. For many, Islam and hatred have become synonymous. Yet historically, Islam's principal gift to the west was, and still is, love. On 14 February we are all, to a greater or lesser extent, Arabs - because when we celebrate romantic love, we are also celebrating an Arab tradition that swept over the Pyrenees in the Middle Ages and completely changed the way we think about intimate relationships.
Cultural historians insist that romantic love is a western innovation, created in the 13th and 14th centuries by the troubadours of southern France. In fact, the first great love songs were performed not by these itinerant French entertainers, but by Bedouin Arabs around 500 years earlier. Indeed, the word "troubadour" is very probably derived from the Arabic word "tarab", meaning musical enchantment.
Convention has it that the troubadours infiltrated the court of Poitiers, where Eleanor of Aquitaine and, later, her daughter Marie de Champagne ensured that the pursuit of romantic love would become the major preoccupation of western civilisation. However, in eighth-century Baghdad, the love poetry of the Bedouin had already inspired a thriving courtly tradition. The poet al-Abbas composed love songs for Harun al-Rashid (the caliph immortalised in The Thousand and One Nights), and the nature of true love was a frequently debated topic.
Arab love poetry often appeared in anthologies - much as it does today. An influential collection was the Masari al-Ushshaq by the tenth-century poet al-Sarraj. The word "masari" connotes "throwing to the ground" or "falling" - thus Arabs were "falling in love" 600 years before the English, who started to do so only after the scholar John Palsgrave introduced the term "to fall in love" in the 16th century.
By the 11th century, Islamic authors were writing love poetry on a much grander scale. These extended works are conspicuously similar to the medieval romances that eventually came out of the court at Poitiers. Arthurian legend has its roots not in a landscape of rolling hills and fairy-tale castles, but in the desert.
The most influential of these early Islamic romances is Layla and Majnun, a story neglected by almost everyone in the west with the exception, surprisingly, of Eric Clapton, for whom it was the inspiration for the hit song "Layla".
Layla and Majnun began life as a collection of independent but related tales about Kais (the "majnun", or romantic fool) and Layla, a Bedouin princess. The story is now best known in a version composed by the 12th-century Persian poet Niza, who took the traditional tales and linked them together with some new ones of his own to produce a longer narrative.
Layla and Majnun contains almost all of the characteristics that became the hallmarks of romantic or courtly literature: love at first sight; a love triangle; forbidden love; idealisation; lovesickness; restless wandering; lack of consummation; and a tragic end. Scenes from Layla and Majnun have surfaced in almost all of the great love stories of the western canon, from Tristan and Isolde to Romeo and Juliet.
A crucial feature of romantic love is that it is supposed to be eternal, which is why rings (having no beginning or end) and precious stones (being immutable) are used to celebrate engagement and marriage. Plato was the first to suggest that love has a spiritual dimension, and yet this idea was not taken up with very much enthusiasm by the classical poets, who were far more interested in the carnal aspects of love (Ovid's "The Art of Love", for example, is really a seduction manual). Islamic poets, on the other hand, found Plato's idea fascinating, and from the 12th century on, Islamic love poetry became more obviously mystical.
The most influential among the new generation of Islamic love poets was Ibn 'Arabi, the author of The Interpreter of Desires. While visiting Mecca, Ibn 'Arabi fell in love with the imam's daughter - a young woman of astonishing beauty. His love for her was, necessarily, unrequited and therefore painful. But it was also revelatory. According to Ibn 'Arabi, earthly beauty is an intimation of heavenly beauty.
The quasi-religious praise of female beauty was incorporated into the love poetry of the troubadours, but western mentality reworked this theme by adding mis-ogynistic overtones. Spiritual inaccessibility gradually became aloofness, which in turn became regal disdain. This led to the emergence of the cold, cruel mistress - a figure who, once introduced into western literary tradition, never really went away. She reappears again in the 19th century as the belle dame sans merci and the femme fatale, and today is an indispensable character in many soap operas.
It is ironic that, whereas Islam responded to sexual frustration by placing women on a pedestal close to God, the west responded by portraying women as frigid and sadistic. Fortunately, the positive aspects of Islamic mysticism were not eradicated by western misogyny (largely thanks to Dante's infatuation with Beatrice), and the adoration of female beauty is still very much a part of the romantic tradition. But this legacy has a downside, which is that we are often disappointed when we discover those we love are not perfect beings but ordinary mortals. Although romantic love might offer a glimpse of heaven, it is still just a glimpse.
It is difficult to read early Islamic writings on love without reflecting on how love unites us - and there is no better proof of this than Ibn Hazm's treatise on the art and practice of Arab love, The Ring of the Dove. Ibn Hazm was born in 994 in Cordova, where Islam had been established for nearly 300 years. With a potent mixture of scholarship, anecdote, self-disclosure and poetry, Ibn Hazm explores nearly every aspect of love: how you can tell when someone is in love, the perils of succumbing to love at first sight, "breaking up", and so on. Remarkably, there is even an alarmingly modern aside in which Ibn Hazm writes "Let me add a personal touch" and proceeds to explain his preference for "blondes".
Inviting the reader into his confidence, he is remarkably good company - witty, observant and wise. That a man raised a thousand years ago in an alien culture can still function as a tolerably good agony uncle is reassuring. It would seem that in matters of love (and weakness for a certain hair colour), man-kind has always been in the same predicament.
The Jungian psychoana- lyst Robert Johnson said: "Romantic love is the single greatest energy system in the western psyche." And he is almost certainly right. As a culture, we have become completely obsessed with love. Books, magazines, pop songs, advertisements, films, opera, plays and paintings reflect our inexhaustible appetite for all things romantic.
Islam's most successful export, then, is not fundamentalism but romance. When we declare our love, the crescent moon rises, Venus burns like sulphur, and the air is scented with rose water and jasmine.
Frank Tallis is a novelist and clinical psychologist. His new book, Love Sick: love as a mental illness, is published by Random House