France divided despite uplifting rallies
While the rally in Paris reflects the determination of its inhabitants to bounce back from the horror of the recent attacks, deep divisions of French society cannot be glossed over easily.
The urge to demonstrate is the urge for mutual reassurance.
When terrible things happen, first we rush for shelter. Then we re-emerge to show each other that we are all still alive.
It is probably what cavemen did when the sabre-toothed tigers passed by.
This week in Paris, many people felt the instinct to hasten home. Murder stalked the streets.
At one point on Thursday we heard that the Kouachi brothers were driving back to town. There were police marksmen at the city gates.
Something primal said: Stay with your loved ones.
But then it was over. And now the urge is to come back on to the streets and to reclaim the land.
That is what it has felt like through the extraordinary scenes of Sunday.
People have made the comparison with the Liberation demonstrations in 1944, and it is apt.
It is apt not just in terms of numbers, but also in how at that moment too French men and women were putting down a marker: France is ours.
But people demonstrate also because they are afraid.
People demonstrate for causes that they feel are under threat. Demonstrating reveals our insecurity.
We demonstrate because we want the hope that comes from knowing there are others who feel as we do.
In France, national unity was the theme of Sunday's monster rally.
But by the logic of demonstrations, national unity is therefore not nearly as secure as the outpouring of mass emotion would tend to suggest.
'Je suis Kouachi'
If you want a sobering counterblast to the dominant mood, have a look at the "Je ne suis pas Charlie" Facebook page. It has received more than 21,000 likes in the last few days.
The mainly Muslim French people who have given a thumbs-up to the page are not supporters of violence. The vast majority have no truck with the Kouachis and Coulibaly.
But they also make clear they will not take part in a national movement that backs people who insulted the Prophet Muhammad.
Over and again they express their anger at what they see as double standards:
Why so much fuss over 17 dead when thousands have died in Gaza and Syria?
Why is it all right for Charlie Hebdo to mock Islam when the controversial comic Dieudonne M'bala M'bala is prosecuted for mocking Jews? Why is one defined as "inciting hatred" and not the other?
Then there are the schools in the high-immigration banlieues where the minute's silence on Thursday in memory of the Charlie Hebdo victims was interrupted by pupils or not observed at all.
France-Info - the national news radio station that normally plays down dissent in the banlieues - ran an extensive report on it, with quotes from distressed teachers.
And if you really want to be shocked, there is a "Je suis Kouachi" hashtag which was briefly trending on Twitter on Saturday.
All of which only goes to prove that there are many French men and women who feel their primary attachment is to Islam, not to the Enlightenment values of post-18th Century Europe.
They feel a constant sense of humiliation, and where they can, they strike back. Normally in petty acts of insubordination. But sometimes in terror.
So France is not united, and the danger is real.
But that is why demonstrations matter. People take part because they work. Seeing such vast numbers of people - of all faiths and backgrounds - united behind a single idea was indeed a moving and uplifting experience.
At the end of a horrid week, morale is back. For a time at least, we are reassured.