Articles in defence of free speech are pouring out of all the usual places. They are eminently unnecessary. We don't need a theory of free speech or a defence of enlightenment liberalism to condemn sadistic murder, or to go through the rigmarole of weighing up the justice of fanatics' pretended motivations.
Liberal principles are at stake here, but they are those principles that constrain democracies from intemperate reactions, the ones that went missing in America after the World Trade Center attacks. Indeed many of the supposed defenders of our liberal values are enthusiastically carrying out the murderers' plan by promoting an us vs them tribalism. The same newspapers who routinely call for banning speech that offends their editors' sense of popular prejudices now pretend to defend the right to be offensive, but only, of course, to those 'who hate our freedoms', the evil muslim threat to civilisation.