Enemies of secularism

Read this article today. I found it enlightening and for me it clarified some of the benefits that a properly secular state offers it's citizens by highlighting some of the big disadvantages of trying to operate parallel legal systems i.e. religiously founded systems like sharia or religiously based privilege like unelected Bishops in Parliament.

I'm in favour of a strictly secular state, one where there is one law (that evolves by consent) which applies to all persons regardless of irrelevant factors such as sex, race, religion, sexual orientation or favourite football team. In practice, allowing a number of parallel systems would inevitably lead to a conflict with this basic position, for example, what happens when numerous parallel legal systems clash, which should take precedence?

Take free-speech for example, it would seem rational that free-speech is synonymous with freedom of conscience and therefore freedom of religion (or none) but still a large number  of religious people have sought and continue to seek to protect their ideas from criticism under the historical shield of "blasphemy" or more recently the modern equivalent of "taking offence", the latter being a slippery slope to the former in my opinion. This is not a new idea, almost all religions (or sects) that have achieved a majority position (usually violently) within a state apply some kind of censorship in their favour; from English language Bibles to The Satanic verses. It seems to be an inherent weakness in the foundations of practically all religions that the followers feel its structural and intellectual integrity is so weak that they need to protect it at the point of sword, letter of the law or threat of a fatwa. It's only increasing secular pressure applied over centuries that seems to move a culture beyond this infantile state.

150 years ago John Stuart Mill nailed the reasons why free-speech is a necessary pillar of any civilised society, he said in "on liberty",

“The peculiar evil of silencing the expression of an opinion is, that it is robbing the human race; posterity as well as the existing generation; those who dissent from the opinion, still more than those who hold it. If the opinion is right, they are deprived of the opportunity of exchanging error for truth: if wrong, they lose, what is almost as great a benefit, the clearer perception and livelier impression of truth, produced by its collision with error.”

I suspect it's the "exchanging error for truth" part that people have a problem with but even to this day, you can't fault his logic without admitting the insecurity of your own position; religious or otherwise.