This latest horror story from Paris has filled me with dread. What with all the kidnappings, the rapes, the bombings and beheadings in the past year. The mass graves, the terrorism of innocent people, the droves of young men burning their passports and pledging allegiance to the harshest edicts of a 7th century philosophy. Where does this instinct to kill and butcher come from? Is it Islam?

The whole Islam / Islamism debate is a minefield, to borrow an unfortunate metaphor. To what extent are you being Islamophobic when you criticise these brutal killers and their methods? There is a danger you will find common ground with some of the worst, most right wing elements in Western society. If you stay quiet about it you make a mockery of the values upon which our society is based – tolerance, empathy, the robust sharing and challenging of ideas, to mention a few. It’s a tightrope.

Islamism should be a core target of sceptics and humanists, because it represents the very worst extreme that blind belief can lead one to. Homeopathy and psychics might screw up someone’s value system and quality of life, but Islamism kills and terrorises, while subjecting all sorts of minorities to cruelty and despair. It’s a depravity – the very negation of free thought and forthright argument.

On the other hand, humanism stands with all people: black, white and brown, rich and poor, native and foreign, male and female, young and old. People from Muslim countries have as much a right to live in peace, security and happiness as anyone else. Castigating and criminalising whole sections of society just because of the actions of a small few is repulsive to me.

People are precious. People are important. The ideas in their minds are not so special. Nobody should ever be killed or injured for their beliefs. but beliefs should never give anyone a license to kill or injure. For that reason, all beliefs should be subjected to robust scrutiny and if necessary, ridicule.

People have mothers, brothers, sisters and friends. Ideas don’t. People shout with joy and weep tears. We worry for them when they get sick. We miss them when they die. Ideas don’t have hospitals, nor do we give them gravestones. People can live on after abandoning damaging beliefs, but it so often happens that damaging beliefs result in death.

Islam is a belief. But mass killings of the past centuries didn’t all need Islam to justify them. It’s just the ogre of the moment. There is something deeper here that can take a belief and turn it into something truly evil. When we criticise the average believer, we taking aim at a convenient target, but it’s the wrong one. It’s radicalism in all its forms that we need to focus on.