It is a laudable aim of the current National Curriculum that pupils "know about big ideas and events that shape the world". But one of the biggest of these is too infrequently studied in schools. We are thinking of the growing loss of faith, over the past two centuries, in a religious picture of the world. David Hume's 18th-century onslaught on arguments for the existence of God was an early catalyst, Darwin's 19th-century attack on what today is known as creationism a later and more devastating one. Nowadays, according to an ICM poll in 2006, the majority of adults in Britain describe themselves as non-religious.

Those who determine the curricula that are taught in state schools insist on knowledge of all sorts of particular facts and approaches to understanding in different subjects. But they do not require any awareness of this revolution in belief, arguably the most dramatic since the origin of Islam. True, the non-statutory RE curriculum now allows for teaching about humanism, but – unlike Christianity and other major world faiths – leaves it optional, and on a par with Zoroastrianism.

Where else might you expect to find an informed and systematic introduction to and examination of atheism and agnosticism? In the science curriculum? In history? English? Citizenship? Your search will be fruitless. There is no curriculum pigeonhole for an idea as big as this one.

Download the new Independent Premium app Sharing the full story, not just the headlines

However, before we decide where to teach about atheism and agnosticism – and it might be that the issue is addressed in a number of subjects, rather as such cross-curricular issues as climate change and ethics are – we first need agreement that students should learn about them.

Indeed, we suspect that initial reactions to our proposals will include rejection of them from those who feel that the last thing they want is humanism on the curriculum. They wouldn't want children to be indoctrinated in unbelief. But it's not a question of getting children to become non-religious; rather of getting them to understand and discuss this major intellectual revolution. RE has, thankfully, abandoned its position of proselytisation. What goes for Christianity and other world faiths on the curriculum should hold for humanism too.

Perhaps it is time here for us to disclose our own positions. One of us is an atheist and a member of the British Humanist Association. The other is a priest in the Church of England. But both of us are also academics at the Institute of Education, University of London, and it is our interest in how school education can be made more engaging, more relevant and more suitable for the 21st century that leads us to our common view on this matter.

What kinds of learning might be required? Young people should think about whether they live in a divine world or a godless one. This points to discussing the standard arguments for and against the existence of God and such questions as the likelihood of life after death. But they also need to discuss whether human lives can have any meaning or point outside a religious framework. And whether people can live a morally good life that is not dependent on religious belief. Historical perspectives are also important, especially the impact of non-religious ideas on intellectual and artistic life over the last 250 years.

Most of this would find its place in the secondary curriculum. But a start could be made with older primary children. Given some guidance, one would expect most young children of, say, nine or 10 years of age, to be intellectually mature enough to think about how the world came about and why we should be good. Of course, sensitivity and respect are required when teaching about such matters. One does not want children to be given the impression that they are going to hell because they espouse atheism or that they are intellectually second rate because they accept the divine inspiration of scripture.

Our argument is part of a broader one about schooling. The school curriculum is not only to do with the workings of volcanoes, the use of the future tense in French, calculations about triangles and the causes of the First World War. Educators and curriculum planners should look up from such comparative minutiae, important as these are in the right place. They should raise their eyes if not to heaven, at least to a more global picture of what education should be about. An understanding of non-religion, like an understanding of religion, is a vital part of this.

The writers teach at the Institute of Education in London