Is society becoming more extreme?

However, this flirtation with outside-the-mainstream views isn't always driven by an extremist mindset. The goal is not necessarily to court controversy; it is to find community.

We must also consider the impact of the digital revolution – and especially what psychologists call 'social disinhibition'. This refers to the fact that people will often take risks and say things online that they'd never say in person.

According to one recent survey, two percent of Brits admit to having insulted someone they don't know online within the past year. Extrapolated across the population that suggests one million people may have deliberately insulted at least one million other people.

Normally circumspect people often feel that the online world represents an alternate reality; a zone where they will enjoy anonymity.

Studies suggest that, comforted by this false sense of security, many of us are prone to express views much more strongly online, on a whole range of subjects. This may add to the perception that our social discourse is becoming more extreme.

Finally, any perceived rise in extremism must be measured against socio-economic factors.

Paris offers a case in point. France has an unemployment rate of over ten percent. Perhaps a sizeable proportion of those who are out of work will be living among the nation's almost five million Muslims.

Dealing with poverty or lack of opportunity is vital to promoting cohesion and respect. However, this will not magic away the problem of militant extremism, for the latter is a moral and ideological issue.

The vast majority of young people from the same background as the Charlie Hebdo killers have already decided to get on with life, using whatever opportunities come their way, or finding more constructive means to bring about change.

Is society becoming more extreme? Certainly there are pockets of radical extremism, but there is still a robust mainstream which agrees on more than it disagrees about.

Our social discourse still looks a little too much to political correctness as a guarantee of cohesion. At times it allows those who lecture the most ardently for tolerance to deny it to others.

We also, at times, refuse to acknowledge facts that are in front of our faces. This, perhaps, is human nature.

We must do more to tackle anti-semitism and other forms of religious bias, at home as abroad. We must also do more to root out the promoters of violent militancy and boost opportunities for those who are legitimately marginalised.

Yet for the most part, in Britain anyway, society is probably still small 'c' conservative in its values. We must treasure what harmony we have and, without compromising proven principles and ethics, work all the harder to nurture it.