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This is what commentor David MacDonald had to say on the subject:

‘To pick an easy target, Monotheism is listed as one of the top fifty. For all their noble beliefs and ideals, it is easy to argue that different monotheistic beliefs’ inability to accept one another have caused more grief and suffering than any other single thing in history and, quite possibly, still do. Somehow we would like to feel a great idea should be positive, but quite a number are very double edged. Ironically, however much suffering it has caused, it would be hard to find an idea that has had a greater impact than monotheism, so if impact is a measure of greatness then it deserves a far better vote, even though many could argue that the impact has far greater negative value than positive.’

What do you think? Can you be an atheist but still acknowledge the good that theistic religion has inspired?

The answer is – so far at least on this site no one thinks that any of them should be considered a contender for the world’s greatest idea!

Here’s John Farndon’s brief reasons why you might consider voting for any of them:

Capitalism
Capitalism is the simple but powerful idea that the world can function best if everyone is left to pursue their own private wealth by buying and selling things, including their own labour, in a free market – an idea that dominates the way most of us live our lives today

Marriage
Marriage is the idea of confirming the natural human urge to mate in a powerful lifelong bond sealed by law, religious oaths or familial and cultural traditions. It is the key personal relationship in most world cultures and is felt by many to be fundamental to society’s stability.

Stirrup
The stirrup hugely increases a rider’s control and balance when on horseback and some believe that the introduction of this simple piece of equipment was the catalyst behind the spread of feudal ideas across Europe, allowing the domination of people by a horse-riding warrior caste.

Surely there are some fans of these powerful ideas out there?

When one of the contributors to our teasingly titled Great Debate recently suggested the greatest idea is Star Trek’s virtual reality room, the holodeck, she did so somewhat apologetically because it’s fictional. But it got me thinking. Just because an idea hasn’t yet become reality, it doesn’t mean it can’t be great. Time travel and teleportation seem great ideas – which if ever realized would seem sensational. And how about ideas for a better world? Thomas More’s Utopia, Einstein’s vision of a world government, Martin Luther King’s dream? And maybe even Marxism, since it has never been realized in the way Marx envisaged. No, they’ve never happened, and may never do, but they remind us that great ideas can give us a vision of a better world, better things, and give us goals to aim for, whether it’s how to make a self-cleaning house or how to bring world peace. Anyone got any great ideas how to clean up the Gulf of Mexico?

Argument has been flying back and forth at the great debate section of the site already, with discussions ranging from whether atheism isn’t actually the lack of an idea to a proposal that Star Trek’s holodeck should have been included on the list!

Followed the latest here and get involved yourself.

Meanwhile, The Internet still leads the poll, with 10.39% of all votes cast so far. Get yours in now!

We’re only a few days into The World’s Greatest Idea and so far, The Internet is the most popular choice, with 8.93% of the vote.

Perhaps people who vote in an online poll are always likely to thing the internet is pretty important, but is it more important to humanity than weaving, pottery or feminism, for instance?

Well, it looks like the debate under way. And it turns to be a much more interesting idea than it first seems – and actually startlingly relevant.

The most ancient idea on the list is the human use of fire. Although it’s hard to be completely sure, it seems our ancestors thought of lighting fires at least 1.9 million years ago. So it’s certainly the most enduring idea.

But is it the greatest? It’s certainly one heck of a powerful idea, and underpins the modern world to an extraordinary degree. So much of our technology, even at the most basic level, hinges on harnessing fire, and though we’re burning oil, gas and coal rather than twigs, the basic idea’s the same.

Fire’s given humankind to the ability unleash and control an incredible amount of power, and it’s hard to imagine a world without that power. Yet on a day when BP announces that it may (or may not) have capped the Deepwater horizon oil leak which threatens the USA’s worst ever environmental disaster, it reminds us just as that there’s no smoke without fire, so there is no fire without fuel.

Could humankind’s most powerful idea also turn out its downfall?

Keep up with the latest news on The World’s Greatest Idea without leaving your Facebook homepage via the project’s page here.

We’ll post the best latest comments, regular updates on which ideas are in the lead and thoughts too from John Farndon, the author behind it all – and more.

Science writer Philip Ball, most recently the author of The Music Instinct, and a member of the panel who decided on the 50 greatest ideas on this site, ponders some of the issues that the project raises on his blog today:

“I’m still not sure whether I did right to join the panel for the online debate being launched by Icon Books on ‘The World’s Greatest Idea’. Well, the title says it all, no? I’m dubious about any view of history as a succession of ‘great ideas’, and the notion of ranking them – abolition of slavery vs the aerofoil vs arable farming – could seem worse than meaningless. Besides, does one rate them according to how intellectually dramatic an ‘idea’ is, or how important it has been to world civilization, or how well it has served humankind, or…? But I acceded in the end because I figured it does not do to be too po-faced about an exercise that after all is just a springboard for a potential discussion about how society produces and is changed by innovation. And there is something grandly absurd about pitching sewerage against romance against simplified Chinese characters. I’m also reassured to see that someone as discerning as Patricia Fara has also taken part. Go on, place a vote – there’s no harm in it.”

Philip’s blog is here. What do you think?

This is the project to find out, once and for all, what the greatest idea humanity has ever had really is…

Stay tuned to hear how YOU – yes, you – can take part in a unique publishing project to be launched in June 2010.