What to do after the occupations of Wall Street and beyond – the protests that started far away, reached the centre and are now, reinforced, rolling back around the world? One of the great dangers the protesters face is that they will fall in love with themselves. In a San Francisco echo of the Wall Street occupation this week, a man addressed the crowd with an invitation to participate as if it was a happening in the hippy style of the 60s: "They are asking us what is our programme. We have no programme. We are here to have a good time."

Carnivals come cheap – the true test of their worth is what remains the day after, how our normal daily life will be changed. The protesters should fall in love with hard and patient work – they are the beginning, not the end. Their basic message is: the taboo is broken; we do not live in the best possible world; we are allowed, obliged even, to think about alternatives.

In a kind of Hegelian triad, the western left has come full circle: after abandoning the so-called "class struggle essentialism" for the plurality of anti-racist, feminist, and other struggles, capitalism is now clearly re-emerging as the name of the problem. So the first lesson to be taken is: do not blame people and their attitudes. The problem is not corruption or greed, the problem is the system that pushes you to be corrupt. The solution is not "Main Street, not Wall Street", but to change the system where Main Street cannot function without Wall Street.

There is a long road ahead, and soon we will have to address the truly difficult questions – not questions of what we do not want, but about what we do want. What social organisation can replace the existing capitalism? What type of new leaders do we need? What organs, including those of control and repression? The 20th-century alternatives obviously did not work.

While it is thrilling to enjoy the pleasures of the "horizontal organisation" of protesting crowds with egalitarian solidarity and open-ended free debates, we should also bear in mind what GK Chesterton wrote: "Merely having an open mind is nothing; the object of opening the mind, as of opening the mouth, is to shut it again on something solid." This holds also for politics in times of uncertainty: the open-ended debates will have to coalesce not only in some new master-signifiers, but also in concrete answers to the old Leninist question, "What is to be done?"

The direct conservative attacks are easy to answer. Are the protests un-American? When conservative fundamentalists claim that America is a Christian nation, one should remember what Christianity is: the Holy Spirit, the free egalitarian community of believers united by love. It is the protesters who are the Holy Spirit, while on Wall Street pagans worship false idols.

Are the protesters violent? True, their very language may appear violent (occupation, and so on), but they are violent only in the sense in which Mahatma Gandhi was violent. They are violent because they want to put a stop to the way things are – but what is this violence compared with the violence needed to sustain the smooth functioning of the global capitalist system?

They are called losers – but are the true losers not there on Wall Street, who received massive bailouts? They are called socialists – but in the US, there already is socialism for the rich. They are accused of not respecting private property – but the Wall Street speculations that led to the crash of 2008 erased more hard-earned private property than if the protesters were to be destroying it night and day – just think of thousands of homes repossessed.

They are not communists, if communism means the system that deservedly collapsed in 1990 – and remember that communists who are still in power run today the most ruthless capitalism. The success of Chinese communist-run capitalism is an ominous sign that the marriage between capitalism and democracy is approaching a divorce. The only sense in which the protesters are communists is that they care for the commons – the commons of nature, of knowledge – which are threatened by the system.

They are dismissed as dreamers, but the true dreamers are those who think things can go on indefinitely the way they are, just with some cosmetic changes. They are not dreamers; they are the awakening from a dream that is turning into a nightmare. They are not destroying anything, but reacting to how the system is gradually destroying itself. We all know the classic scene from cartoons: the cat reaches a precipice but goes on walking; it starts to fall only when it looks down and notices the abyss. The protesters are just reminding those in power to look down.

This is the easy part. The protesters should beware not only of enemies, but also of false friends who pretend to support them but are already working hard to dilute the protest. In the same way we get coffee without caffeine, beer without alcohol, ice-cream without fat, those in power will try to make the protests into a harmless moralistic gesture.

In boxing, to clinch means to hold the opponent's body with one or both arms in order to prevent or hinder punches. Bill Clinton's reaction to the Wall Street protests is a perfect case of political clinching. Clinton thinks that the protests are "on balance … a positive thing", but he is worried about the nebulousness of the cause: "They need to be for something specific, and not just against something because if you're just against something, someone else will fill the vacuum you create," he said. Clinton suggested the protesters get behind President Obama's jobs plan, which he claimed would create "a couple million jobs in the next year and a half".

What one should resist at this stage is precisely such a quick translation of the energy of the protest into a set of concrete pragmatic demands. Yes, the protests did create a vacuum – a vacuum in the field of hegemonic ideology, and time is needed to fill this vacuum in a proper way, as it is a pregnant vacuum, an opening for the truly new.

The reason protesters went out is that they had enough of the world where recycling your Coke cans, giving a couple of dollars to charity, or buying a cappuccino where 1% goes towards developing world troubles, is enough to make them feel good. After outsourcing work and torture, after the marriage agencies started to outsource even our dating, they saw that for a long time they were also allowing their political engagements to be outsourced – and they want them back.

The art of politics is also to insist on a particular demand that, while thoroughly "realist", disturbs the very core of the hegemonic ideology: ie one that, while definitely feasible and legitimate, is de facto impossible (universal healthcare in the US was such a case). In the aftermath of the Wall Street protests, we should definitely mobilise people to make such demands – however, it is no less important to simultaneously remain subtracted from the pragmatic field of negotiations and "realist" proposals.

What one should always bear in mind is that any debate here and now necessarily remains a debate on enemy's turf; time is needed to deploy the new content. All we say now can be taken from us – everything except our silence. This silence, this rejection of dialogue, of all forms of clinching, is our "terror", ominous and threatening as it should be.