'A spectre is haunting Europe," wrote Karl Marx and Friedrich Engels in The Communist Manifesto, "the spectre of communism." The revolutions of 1848, which led the two men to publish their historic pamphlet, may have been defeated by the forces of the status quo, but Marx and Engels' choice of words was quite appropriate: vast movements of emancipation are often propelled by something thoroughly intangible, an overpowering spirit of change.
Looking back on the Arab revolts this year, that detail is worth remembering. Journalists and academics have sought to explain what happened through quantifiable yardsticks - a youth bulge, disparities between elites and the poor, rising unemployment and so on. But these factors would have counted for little without a meta-narrative unifying and channelling popular frustrations across the region, infusing them with a determination to overthrow their oppressors.
When Tunisians ousted the kleptocratic regime of President Zine El Abedine Ben Ali last January, this was initially regarded as a happy coincidence. Even the outbreak of protests in Egypt soon thereafter did not immediately appear to represent the onset of a wave sweeping the region. Or perhaps it did, and the less imaginative, or the less romantic (and I count myself among them), failed to grasp that the narrative of emancipation had already taken hold.
Yet the fall of President Hosni Mubarak focused even the dullest minds on that reality. The historian Robert Conquest used a luminous term as the title of one of his books, "the dragons of expectation", borrowed from a collection of old Norse poems. For Mr Conquest, otherworldly expectations, bolstering a sense of unqualified ideological truth, were frequently behind the great crimes of the 20th century. However, we can employ that expression less pessimistically in the context of the Arab uprisings, to convey what has happened in many Arab societies, overwhelming, dragon-like, everything before it.
When protesters in Tunisia and Egypt prevailed against their security apparatuses, Arabs elsewhere began inserting themselves into that grand narrative, as success in two countries seemed preordained to bring success in others. That moment was essential, with Libyans, Syrians, Yemenis and others carried forward by transnational momentum of which they saw themselves a part. Here is when one discovers the courage to go into the streets, and when regimes react with the brutality that brings even more people out into the streets.
The role of media has been significant, principally in transmitting the meta-narrative. Social media in Tunisia, Egypt and Syria have played an important mobilising role, while highlighting that there are domains that regimes do not control. Arab satellite channels, above all Al Jazeera, have transported the dragons of expectation from one society in rebellion to the next, heightening outrage through their use of dramatic footage, reinforcing the interpretation of events as one of victims winning out against consuming injustice.
The influence of the stations was demonstrated when Al Jazeera and Al Arabiya, reflecting the political uncertainties of the regimes financing them, took weeks before siding with the protesters in Syria. This prompted the Syrians to demand more attention, and before long Al Jazeera, partly a prisoner of the narrative it had helped propagate and could not abandon for fear of losing its credibility, took sides. The station was far less militant over Bahrain, to its detriment, but the violence in Syria was of a scope that permitted no ambiguity.
Powerful narratives often displace others. Recall how at the end of January, Syrian President Bashar Al Assad sat with the Wall Street Journal and offered a sanguine assessment of his rule. Arabs were up in arms elsewhere, but not in Syria, Mr Al Assad pointed out, because Syrians had an ideology and a cause, so that on foreign policy they were closely aligned with their regime. "When there is divergence between your policy and the people's beliefs and interests, you will have this vacuum that creates disturbance," the president said.
Here was one irony wrapped in another. Mr Al Assad recognised the sway of ideas, but did not imagine that ideas would soon threaten his rule. And there was a greater irony. The president did not foresee that the narrative he held up as a basis for why he and the Syrian people were in purported harmony - their common embrace of a narrative of resistance to America and Israel above all - would count for little in the face of demands by Syrians for internal transformation.
That's the real message from the Arab world this year. Societies may sympathise with foreign policies opposed to the West, the United States and Israel, but they no longer will allow regimes to use foreign antagonisms to validate stifling, sadistic, security-dominated political systems at home. Nor will they tolerate giving foreign matters precedence over their own welfare and that of their children.
That is why, at some stage, the meta-narrative of emancipation cedes way to more worldly concerns. That is the trickiest part. Once you've got rid of the tyrant, what social contract does a society put in his place? In Egypt and Libya, societies are struggling with the answer, while in Tunisia the consensual resort to institutions has helped clarify one. In Syria, the repression is ongoing with the emancipatory narrative continuing to undermine Mr Al Assad's authority.
Whatever the outcomes in the Arab world, the impulse of liberty, once unleashed, justifies itself. Thank those Arab leaders who are confronting angry populations for having allowed that impulse to take on a life-force of its own, so that barricade by barricade it is devouring them.
Michael Young is opinion editor of the Daily Star newspaper in Beirut and author of The Ghosts of Martyrs Square: An Eyewitness Account of Lebanon's Life Struggle