The first recorded story of a Christian icon is related by the early church historian Eusebius of Caesarea, who tells of the incurable illness of King Abgarus of Edessa. Hearing of the miracles performed by Jesus, the ailing king wrote to him imploring for his help. Jesus, who was otherwise engaged at the time, took a linen cloth and pressed it against his face. Imprinted with his heavenly visage, Jesus sent the cloth to the king to heal him in his stead. Through this act of divine multi-tasking Christ not only created the visual archetype for the multitudes of religious icons that would pepper churches, theological debates and conspiracy theories for centuries to come, but also remarkably seemed to foretell the invention of the iron-on T-shirt transfer.

Two thousand years on and icons have multiplied exponentially, in number, size and theme. No longer strictly theological objects, icons now come in all shapes and sizes — representing political, cultural and economic deities — and the term “icon” has become so diluted that it now acts as little more than a synonym for “emblem” or “symbol.” But vestigial differences in meaning remain. Perhaps the most precise way of identifying a true icon is to consider the rage it inspires. Take, for example, the curiously parallel obliteration of the Buddhas of Bamiyan in Afghanistan in March 2001 and the twin towers of the World Trade Center six months later: One can clearly recognize both the time-honored religious icon and the new-fangled cultural icon. For icons, it seems, are most easily identifiable not when they perform miracles, but when they burst into flames.

An icon is, in its traditional sense, a painting, sculpture or mosaic of anything considered holy or divine. Quite unrelated to portrait painting, the icon does not seek verisimilitude with the real but rather a representation of the ideal. Its aim is to provide a focal point for belief, acting as a window that opens onto the heavens. While both Islam and Judaism stress the impossibility and forbidden nature of making graven images of their deities, Christianity has always been remarkably conflicted about the idea. Although the second commandment strictly prohibits the making of any “graven image,” the incarnation of Christ in human flesh on Earth would seem to wholly justify the use of physical matter as an aid to worship.

Yet standing as it does on the theological border between the sensory and spiritual worlds, the icon has often been accused of overstepping its theological remit. For such has been the popularity of the icon’s visual shorthand that it has often become not so much a guide to faith as an idol that is worshipped in and of itself. In the seventh and eighth centuries AD a string of Byzantine emperors banned icons in an attempt to prevent such idolatry (and, it is suggested, to try to halt the catcalls from the icon-free Islamic nations surrounding them). Against them stood the popes who, threatened by this attack on their religion and having long used icons to bring the illiterate into the fold, insisted that they should remain. Thus began the bloody Iconoclastic Wars, in which fleets were sunk and thousands were killed, and whose vehement and violent anti-iconic (and anti-aesthetic) sentiments would not be rivaled until the English Reformation and Mao’s Cultural Revolution. It was not until the Second Council of Nicea in 787 AD that laws were passed that stressed that icons could be venerated, but not worshipped: a fine distinction.

This decree has proved particularly difficult to uphold. Icons are famed not only for acting as earthly windows onto the heavens, but also for allowing the divine to flow back into reality. This supernatural leakage can be seen, for example, in the Black Madonna of Czestochowa in Poland, a fourteenth century painting that is surrounded by discarded crutches, bandages, and eyeglasses — a testament to its ability to heal the sick. Is the Black Madonna a particularly “open” window onto the divine world, or is it itself imbued with divine powers? Are people worshipping the deity behind it, or the painting itself?

Perhaps due to this doctrinal uncertainty, the icon soon shook itself free from its religious trappings and entered the secular world, where its appeal as a mode of signification has only grown. The icon is alluring because it satisfies our desire to give a recognizable face to the complex. Take, for example, the thoroughly lay usage of the term in computing. When we surf the internet or write emails we place our faith in icons — small images representing extremely complex strings of code. We use the “computer icon” to traverse this technological labyrinth, blithely avoiding the strings of 0s and 1s which prop up the system, just as traditional religious icons allow believers to bypass the centuries-old tangle of religious dogma and cut straight to the divine.

The same is true when we apply the term to people. Madonna — she of the pointy bras, not of the sacred heart — is consistently described as a “cultural icon” because she defined a way of living in the 1980s and 1990s. She is a window onto the complex thoughts of our own youth, our own fascination with sex and our often sublimated desire for fame and acknowledgment by the world. She is our gateway to a seductive, unholy ideal.

Yet our contemporary usage of the term “icon” seems to display its religious heritage mainly/mostly when applied to merchandise. It was Marx who first suggested the fetishistic nature of the commodity in Das Kapital, but he underestimated the depth of religious feeling we have for products today. They carry not only an aura of religion but the same transformative power in the real world ascribed to traditional icons. It is brand-name goods in particular that are most similar to the religious icons of old, standing on the cusp between the real world and the consumer’s Platonic ideal, the otherworld for which advertisers are the high priests. Like religious icons, branded products allow individuals to commune on an individual basis with their chosen deity — Success, Attraction, or Popularity.

This being the case, our era’s true iconoclasts reveal themselves not as the religious fundamentalists of the Taliban but as those for whom Naomi Klein’s anti-globalization manifesto No Logo (2000) is a sacred text. Klein’s demand that we break free from the influence of brand-name products, and in so doing bring down the multinationals and their sweatshops, is little more than a cry to free people from capitalist idolatry. Yet five years on from that book’s publication, such a political revolution does not seem to have any better chance of long-term survival than the bloody but brief iconoclastic revolts of the Byzantine emperors. For if one looks again at Eusebius of Caesarea’s story of the first Christian icon, Jesus’s demonstration that the divine can spread itself across many material forms, that the power of the religious archetype (the Jesus brand, if you prefer) can be mass-produced, and transported, at minimal cost, to affect people many miles away, is surely one of the earliest examples of globalization in action. And if today’s capitalist icons share such strong theoretical links with those icons of religion, might they not also share their longevity?