I've a piece thinking about the significance of the RSA's spirituality project in the Church Times today…

The "spiritual but not religious" are the largest group of individuals in the UK, according to the think tank, Theos. Its recent poll, which shaped the inaugural discussion on the new Things Unseen podcast (http://www.thingsunseen.co.uk), found that only 13% of adults agree that human beings are purely material with no spiritual element. That much may be unsurprising to members of the Church of England who routinely work at the interface of regular and irregular church-goers.

What does seem to be a new phenomenon, though, is that avowedly secular groups are seeking to explore the spiritual dimension in life - and not just privately but through meetings and action. A case in point is The Sunday Assembly, also called the "atheist church", although its founders are keen to stress that Dawkins-like rallies are not its raison d'être. In only a few months, it has drawn hundreds of people and led to several "church plants".

Some will feel sceptical about this new spiritual questing, much of that unease focusing on the word "spiritual" itself. In much the same way as "sin" now spontaneously throws up associations of chocolate and lingerie, so "spirituality" can mean little more than warm feelings and a fondness for scented candles. Where is the ethical engagement in this touchy-feely piety; where is the embrace of suffering; where the intellectual weight? The issue is being tackled head-on by another self-consciously secular organisation, the RSA in London. Founded in 1754, at the height of the English Enlightenment, and usually associated with practical policy development, the society became interested in recent work on human wellbeing. The s-word kept coming up, particularly in the domain of positive psychology, the academic movement that lies behind many of the current political attempts to think about mental health as well as economic wealth. It identifies spirituality as a "signature strength".

So now, Jonathan Rowson, one of the directors at the RSA, is leading a year long project, that will include workshops and public events, to help make spirituality "more tangible and tractable". The evidence shows, he believes, that personal growth and social engagement are nurtured when people have a spiritual perspective, are informed by spiritual experience, and shape their lives with spiritual practices. He argues that the world's main policy challenges, from climate change to rising levels of obesity, may ultimately be spiritual in nature because they are about our struggle to align our behaviour with our values. Spirituality addresses such inner conflicts. That so many seem unable to resolve them may be, in part, a product of a culture that is starved of that which can motivate us at the deepest levels.

The first of the public events was held on 9th October - the discussion can be found as a podcast on the RSA's website - and it was striking how apologetic the contributors were for even talking about the subject. Rowson thanked the head of the RSA, Matthew Taylor, for the "reputational risk" involved in sponsoring the project. Other participants talked of feeling nervous and unsure, even whilst confessing that religion was central to their lives. Spirituality is a kind of taboo. Intellectuals, politicians, the media and even clergy can be as embarrassed by it as Victorians supposedly were by exposed piano legs.

It must be because we live in a world that has been profoundly shaped by a rejection of the spiritual dimension. David Bentley Hart makes the case in his new book, The Experience of God (Yale University Press: 2013), arguing that the philosophical and scientific paradigms that shape the contemporary imagination, to the extent of determining what can and cannot be perceived of life, have put off-limits subjects like faith, the soul, the implicit and so on. "The philosophical tendencies and presuppositions of any age are, to a very great degree, determined by the prevailing cultural mood or by the ideological premises generally approved of by the educated classes," he writes.

I think that is true. Listen to BBC Radio 2 or 4 any day of the week and you will be drawn into a worldview that finds evolutionary speculations about the origins of love or music engaging and acceptable, whereas wondering about truth or transcendence gets kid-glove treatment. That spiritual sensibilities, the sources of human purpose and meaning, are ring-fenced is surely part of the reason we find ourselves so frequently to be ethically and personally at sea.

But perhaps the nascent secular interest in spirituality marks a change. The task of redressing the imbalance is about nothing less than shifting mindsets, but when unexpected parties - like the RSA or self-conscious atheists - come out about spirituality, new connections become possible. Conversely, those who needed no persuading but find the s-word difficult must swallow their disdain and be prepared to treat the word as a placeholder for a society striving to revive these half-forgotten insights about what it is to be human.

I suspect that some steps will be easy to make. As the philosopher Robert Rowland Smith put it during the RSA discussion, many well-meaning people can agree on a notion of spirituality that is essentially a form of ethical humanism - the intuition that community, wonder and helping others adds value to life. But does that get to the heart of what is meant by spirituality? Isn't it rather engaging with the possibility that the source of human vitality and purpose ultimately lies beyond human capacities and understanding; that life is sustained by what theists call God? The difficult moment for the new spirituality will arrive when those who have put their faith in secular enlightenment are confronted with the possibility that it is not enough.