On Saturday, the atheist philosopher, neuroscientist and author Sam Harris will be debating the Canadian psychologist Jordan Peterson in the 3Arena, as part of the ‘Winning the War of Ideas’ event.

Though Peterson is the headline attraction for many attendees, Harris has been in the public eye for much longer, having been one of the foremost figures within the New Atheism movement for over a decade. Indeed, one of his best-known books on atheism was his ‘Letter to a Christian Nation,’ published in 2006.

At the time, the unpopularity of President George W. Bush led to much condemnation of the so-called ‘Religious Right’, socially conservative American Christians who supported Bush and his Republican Party.

Harris structured his short book in the form of a letter to a conservative American Christian; a group narrowly defined by Harris himself. In his own modest words, Harris sets “out to demolish the intellectual and moral pretensions of Christianity in its most committed forms” as part of a broader effort to push for a fully secular society.

While the overall themes are universal in their scope, Harris’ main focus is on conservative religious believers within his own country, who thanks to their association with an unpopular leader were being subjected to ever-greater criticism at home and abroad.

Harris pulls no punches in decrying their influence on American society, and in suggesting that America was sullied by the existence of such widely-held beliefs, in contrast to overwhelmingly secular countries elsewhere in the West.

“Among developed nations, America stands alone in these convictions. Our country now appears, as at no other time in her history, like a lumbering, bellicose, dimwitted giant.”

Though the book is written as a letter to an American Christian, the content and tone suggest that its intended audience is other atheists. Many specific charges are made against the tens of millions of American who hold Christian beliefs, yet many of these accusations demonstrate a lack of consideration of broader issues, as well as insufficient knowledge of the minds of ordinary believers.

One such issue was the funding of embryonic stem cell research which came to prominence around 2006. The opposition of many American Christians to research that destroyed human embryos angered many secularists, Harris included. On this point, he will brook no dissent, and labels all opposition as “obscene”.

“Given the accommodations we have made to faith-based irrationality in our public discourse, it is often suggested, even by advocates of stem-cell research, that your position on this matter has some degree of moral legitimacy. It does not. Your resistance to embryonic stem-cell research is, at best uninformed. There is, in fact, no moral reason for our federal government’s unwillingness to fund this work,” he writes.

No degree of moral legitimacy; for one who so frequently criticises the influence of faith on individual reason, Harris’ position here is incredibly absolutist and dogmatic.

In fact there are plenty of reasons to express qualms about the deliberate destruction of human life, even in its earliest stages; not to mention the difficulty in determining what the limits of embryonic experimentation should be.

The recently-deceased and famed columnist Charles Krauthammer wrote very eloquently on this subject. Being an agnostic, a trained physician and confined to a wheelchair due to a spinal injury, Krauthammer had a unique insight into the issue, and a vested interest in seeing as much scientific experimentation take place as possible.

In spite of all this, he was sympathetic to those religious citizens who opposed embryonic stem cell research. Though he disagreed with equating an embryo with a grown human, and he did favour allowing research on discarded embryos from fertility clinics, Krauthammer drew a line at creating life for the purpose of destroying it, writing that he “did not believe that a human embryo is the moral equivalent of a hangnail”.

Krauthammer was not alone in this concern; with the pioneer of embryonic stem cell research Dr. James Thomson stating that “if human embryonic cell research does not make you at least a little bit uncomfortable, you have not thought about it enough.” For Harris though, the issue is black-and-white.

Harris acknowledges that many Christian believers are motivated by their faith to help the poor and unfortunate, but insists that secular people do so also. Of course, he does not attempt to quantify secular charity as opposed to religious charity: knowing that such a comparison would be detrimental to his argument.

Upon examination, American conservatives actually prove far more generous than their miserly liberal peers. The most generous category of all? Frequent churchgoers.

It gets worse. Towards the end, Harris drops any pretence of engaging with the arguments, preferring to equate religion with rape, while comparing need to eradicate religion with efforts to abolish slavery in the early history of the United States.

These tirades are unfortunate, not for its offensive nature, but because of the fact that Harris – at his best – is a brilliant thinker, as well as a gifted writer.

He owes much of his fame as a polemicist to these gifts, and to his courage in fearlessly condemning the abuses within the Islamic religion, abuses which he rightly insists find support within their religious scriptures and the actions of their prophet.

Whereas others like to focus on the soft targets – such as Evangelical Christians – Harris has spent years raising concerns about Islamic extremism. For this, he has gained an undeserved reputation as an Islamophobic bigot, while other clueless voices on the left such as Ben Affleck have labelled him a racist.

If he is critical of Christianity also, it is not because he is attempting to gain popularity, but because he believes what he is arguing for to be truth.

More importantly, Christianity needs its loyal opposition, as any who have studied Irish history should know. For without secularism, clericalism is the inevitable outcome, and one which must be guarded against at all times.

While secularism can prove to be intolerant of faith, the separation of church and state which has been achieved in the Western world has been to the benefit of all parties.

We will never agree where the precise lines should be drawn between the two, but secular voices in previous centuries have been invaluable in insisting that they to be drawn somewhere at least.

Furthermore, the rise in scepticism and the greater willingness of non-believers to criticise dogma has forced Christian churches to examine their more questionable teachings. The abandonment of the absurd and cruel idea of limbo is a good example of what this has led to, and indeed Harris references it here.

And while Harris is wrong to accuse all Christians of believing that they are saved and all others are damned, there is no doubt that throughout history many clergymen have told their congregations exactly that. The fact that such sermons are no longer heard is a testament to the degree to which secularism has changed Christianity, and changed it for the better.

However the positive aspects of secularism are not advanced by an ignorant screed such as this, and Sam Harris is capable of better. He will have to try better with his next correspondence if he wants the Christian nation to write back.