But in the aftermath of the attack it is not freedom of speech that is under threat. Still less should progressive opinion rally to the defence of what Charlie Hebdo itself publishes. Rather the priority is now to resist the wave of Islamophobia that is already being unleashed in France and way beyond, as usual tarring all Muslims with the brush of a handful of extremist murderers.
First on Charlie Hebdo. While nothing that has appeared in Charlie Hebdo even minimally justifies the murderous assault on its journalists, the attempt to portray the magazine as a bastion of radical criticism and even part of the armoury of the left is a falsification. Rather it is a populist right-wing libertarian rag, which delighted in producing the most offensive possible images to accompany its outpourings of spleen. Its targets were the marginalised, primarily Muslims but often it was sexist and homophobic too.
Despite the attempts to present it as uniformly critical of all the major religions, and stridently secular, it has had a particular profile for its cartoons targeting Islam. In 2006 it hit the news by reprinting the highly controversial, offensive Danish cartoons that had led to protests by Muslims in many parts of the world.
The cartoons it generates on Islam and Muslims generally use exaggerated Semitic features for the characters lampooned.
Moreover such cartoons do not land in neutral territory. Ridiculing the Pope on the one hand and caricatures of Muslims on the other are neither the same nor have the same social impact.
With a wave of Islamophobia sweeping through many countries of Europe, including France, such provocations at the very least play to the pre-existing climate of Islamophobic racism, prejudice and hatred, and at worst contribute to it.
Nor is this just about rejection of the ideas of Islam. On the streets it leads to daily petty racist assaults on Muslim people – spitting, abuse, women's headscarves being torn off, graffiti. It has also led to serious and life-threatening attacks, including murders. The bombings of mosques in Sweden over Christmas are a case in point. And politically it is building support for parties and street-based movements that have a dangerous echo of the Nazis in their substitution of Muslims for Jews as the target for their hatred.
The liberal principle of freedom of speech is summed up in the statement: "I disagree with what you say but I will defend to the death your right to say it." At the very least that is what the left should be saying about Charlie Hebdo.
But this extensive version of the right to freedom of speech is limited by the other great liberal principle that individual freedom, including that of speech, can and must be curtailed by the prevention of harm to others.
In Britain this has meant legislation that precisely limits the freedom of speech where such speech can be deemed to incite racist violence. It is questionable whether all of the cartoons published by Charlie Hebdo would have escaped this judgement if published here. And it is to be hoped that if a publication appeared in Britain that produced such anti-Islamic provocations on a weekly basis that it would be met with censure, protest and boycott, if not legal action.
Apart from the dead and injured, the other victim of the horrendous murders in Paris this week is not the freedom to peddle anti-Islamic provocations like those of Charlie Hebdo, which it can be guaranteed will continue, but the Muslim community in France and the civil liberties of all. In the 24 hours since the murders there have been attacks on Muslim places of worship, including shots fired and an explosion at a kebab shop near a mosque.
The attack at Charlie Hebdo has already been used by Marine Le Pen to attack Islam as a "murderous ideology" and call for the reintroduction of the death penalty. Police repression of France's Muslim communities has already been a concern, this is set to increase.
Across Europe parties of the extreme right are seizing on the events in Paris to justify their politics of anti-Islamic hatred and build support for populist and neo-Nazi solutions to the crisis still afflicting working people across the continent.
Rather than get pulled into defending Charlie Hebdo or others to publishing provocative, racist, sexist, homophobic and Islamophobic material, the correct response to the murderous assault in Paris is to come to the defence of the beleaguered Muslim community.
“Je ne suis pas Charlie Hebdo, je suis Musulmane.”
Jude Woodward is a long-standing anti-racist activists and an officer of Unite Against Fascism