Fear makes hypocrites of us all. Conservatives pump taxpayers’ money into security services from a public sector they habitually denounce as wasteful. Progressives make excuses for reactionary movements they would describe as fascist in other circumstances. Everyone stands on their heads and says the opposite of what they once believed, while all the time assuring passers-by that they haven’t changed in the slightest.

As you do not buy the Observer to hear how wonderful you are, allow me to spell out the contradictions in liberalism. On the one hand, traditional liberals say they must oppose political Islam. It is oppressive in its attitude to women, freethinkers and gay people, dogmatic in its intolerance of believers in other religions and none, and contemptuous of democracy and human rights. In Saudi Arabia and Iran, it mandates theocracy. In Syria and Nigeria, it justifies slavery and the mass murders of unbelievers.

Traditional liberals say we should oppose its non-violent and violent sectarianism as vigorously as we oppose Christian, Jewish, Hindu or any other form of sectarianism. Let your enemies play the race card and call you an Islamophobe if they must. Liberal Muslims and ex-Muslims need your support and you need to show that you are not living a lie.

Courageous though these fine words sound, fear drives them. If fanatics do not threaten the peace or use the law to enforce their prejudices, no one worries about them. I do not feel a duty to defend liberal Anglicans from evangelicals because I do not fret that arguments within Anglicanism will lead to terrorism and war. Instead, I happily pass my days without thinking about Anglicanism at all.

Against traditional liberalism stands multicultural liberalism, which the majority of people who call themselves “progressives” believe. An unimprovable example of how it turns old certainties on their heads came two days before the Paris massacres. In an interview, Keith Vaz MP appeared to agree that a blasphemy law might be needed. It is symptomatic of our time that Vaz is not a Tory traditionalist who thinks it wrong for impious critics to mock the beliefs of the faithful, but a Labour politician. In general today, the left rather than the right, multicultural liberals rather than Tories, are the most likely to defend religious conservatism.

There can be no compromise between these two versions of liberalism and we should have the honesty to admit it. For all its faults, the US retains the capacity we have lost to debate ideas in what remains of its serious press and has marked out the dividing line.

The great moral philosopher Michael Walzer argued in Dissent magazine that people who considered themselves to be leftwingers or liberals ought to “engage co-operatively with Muslim, and also lapsed Muslim, opponents of zealotry – and give them the support they ask for”. His intervention drew many an outraged responses, as you would expect. The best came from Shadi Hamid in the Atlantic. Even though I think his argument is disastrous, I will try to explain it fairly.

It should not be surprising that some French Muslim schoolchildren refused to obey their teachers’ instructions to honour the murdered journalists of Charlie Hebdo and Jews of the Hyper Cacher supermarket, he said. Muslims the world over do not believe that religion should be separated from politics. In France itself, large numbers of Muslims want satires of Muhammad and the Qur’an criminalised. Britain is not so different: 28% of Muslims said they would “prefer to live under sharia law”. His figures were from 2007, but a survey for the BBC in 2015 found 27% of British Muslims saying they had some sympathy for the motives behind the attacks on Hebdo.

This is just the way the world is, Hamid concluded. We had to accept it because “a liberal society cannot truly be liberal without allowing citizens to express their own personal illiberalism, as long as they do so through legal, democratic channels”.

Which is true, as far as it goes, but must surely apply to white conservatives accused of sexism, racism and homophobia and, if Hamid is being consistent, of Islamophobia too. They are the way they are, too, and we must respect them as long as they are peaceful. Multicultural liberals do nothing of the sort, however. They are always trying to police debate. Supporters of laws banning mockery of Muhammad, for instance, which the last Labour government almost succeeded in passing, do not want to tolerate “diverse” beliefs. They want to censor them.

A trap springs when you fail to realise that tolerating is not the same as respecting or endorsing. A tolerant society does not abandon the freedom to argue. Instead of defending that freedom, multicultural liberals imagine a bloc – “the Muslims” – assume the views of its conservatives represent all within in it, and then assume the minds of religious conservatives can never be changed. As the world now is, they intone, so it must always be. The worst of it is, they abandon liberal Muslims and instigate a politically correct racism as they do it.

The Law Society as good as told every solicitor in England and Wales that a Muslim woman was worth half as much as a man in sharia compliant wills. Universities UK said Islamists had a human right to demand the segregation of women at public meetings. They would never say that a white woman was worth half a white man or tell her she must sit at the back of the hall at meetings. But when it comes to other cultures, they are happy to play the misogynist.

Fear has driven multicultural liberalism, too, and that fear will be back with a vengeance after Paris, along with the double standards and demands for new authoritarian laws that always accompany it.

Progressives condemn “clash of civilisations” rhetoric and deplore the racism of Marine Le Pen and Donald Trump. But their attempts at appeasement show that they are not so different. They also treat Muslims as “the other” rather than fellow citizens and insist that different rules must apply to them in case they turn violent.

I have no idea whether traditional liberal principles will help slow the wave of religious violence. For now, it seems as if nothing will. But I do know that if we don’t stick by them we will end up with an even more unjust society than we already have.