Charles Leadbeater is one of the world’s leading experts on innovation in companies, cities and culture, whose TED talks on innovation have been downloaded by more than 1.5m people. Described by the Financial Times as the UK’s leading innovation expert and ranked by Accenture as one of the world’s leading management thinkers, he has written a string of bestselling books. His work with the Centre for London includes The London Recipe and Hollow Promise.

From north to south, east to west, London is dotted with greens and commons. Could they be the model for managing quite different kinds of assets? We need a new fund to help promote the common life.

London’s parks and green spaces are a history lesson in how the ebb and flow of wealth and power has shaped the city. There are the Royal Parks, a bequest from the monarch and once only for the gentility; and the string of parks, like Lloyd Park in Walthamstow, which started life as the grounds of an aristocratic home. There are parks that are remnants of London’s links to agricultural production: Highbury Fields, once a market garden; and London Fields, a place where sheep were gathered before being driven to market. And of course there are the classic 19th-century parks, like Victoria Park, designed by social reformers to provide recreation for the masses, to make workers healthy and to act as schools for city living, where people could learn the habits of civility.

London likes to claim that it is the world’s best city. What kinds of world-leading green spaces should modern London bequeath to the future? In the rush to grow, to accommodate the inflow of foreign investment and new workers, how can green space make the city more successful by allowing it to be more human, fairer, calmer and more at ease with its own diversity?

The best way to have a new idea is often to recuperate a discarded old one. In London, a home-grown solution is waiting to be rediscovered: the city should create a new generation of the commons. If we want to the city to be liveable for people on median incomes, we should see ourselves as commoners, inhabiting a shared, common space governed by careful, mutual self-management. The green spaces that make up London’s original commons should serve as the inspiration for this much larger idea of the common life that binds the city together. Green spaces matter for all sorts of environmental and ecological reasons. But they also matter socially and politically, because they can inspire us to think of the kinds of modern commons we could create in other walks of life.

London is blessed with commons: Ealing, Clapham, Chiswick, Wandsworth, Clapton, Acton, Gumping (in Bromley), Ham (in Richmond). Hackney Marshes, Hampstead Heath and Blackheath are common land. A long list of greens that are common land remind us of London’s history as a collection of villages: Goose Green, Cuckoo Green, Acton Green, Back Green.

Commons and greens are places that seem democratic yet pastoral, historic yet part of the modern city. They are one reason why most people in London have hyphenated identities. No one who lives in London just comes from the city as a whole. They say they come from Stoke Newington or Parson’s Green, Wimbledon or Bethnal Green. Often, those places trace their identity back to a village and a piece of common land. In a relentlessly busy, highly transactional, always-on city, green spaces allow us some quiet, respite and calm.

It is not hard to get a little dewy-eyed about the ancient roots of commons. As the online activist network On the Commons puts it: ‘We believe it is possible to remember, imagine and create a society that goes beyond the constructs and confines of individual ownership. To work on the commons is to work to enliven the deep and ancient memory we all hold of egalitarian and reciprocal relationship, of belonging, of authentic community and of love, wonder, and respect for the natural world.’

For some, the commons are places where the non-conformist, egalitarian English radicalism of the Diggers and Levellers took root. Commons are still places of everyday democracy, where we learn how to manage being in a shared space with different people without anyone telling us what to do. We like green spaces because we like the kind of people we become there: relaxed, trusting, civil, empathetic. Small green spaces, in particular, are like objects of public love, places of shared affection and attachment, which are more likely to allow people to feel attached to one another, as if they are engaged in a common life with common goals rather than just a mad rush to get to and from work and the shops.

The idea of the commons as Arcadian is not very helpful these days; nor, it turns out, very accurate. The original commons were pragmatic and eclectic, often supporting a mixed economy, as they do now.

The commons came into legal being in 1215 when King John signed the Magna Carta, recognising the existing common law and codifying the rights of people who had no land. These were existing rights, embedded in ancient custom and practice: the right to use the commons came up from the people, not down from the monarch.

While common land was usually legally the property of an aristocratic landowner, he was required to continue to allow access to local people. As one history of the Old English open field commons explains, the open, democratic commons co-existed with particular rights in it: ‘The state, as represented by the king, might thus have the right to large trees most suitable for use in naval construction and a nobleman owning estates covering a large region might have rights to certain game animals, while a certain farmer from the village had the right to pannage for his swine and a village cottar the right to gather firewood from the ground.’

This pragmatic, hybrid approach to shared, multiple forms of ownership is precisely what we need now in London – not least in the field of housing, because both the market and the state are in danger of letting people down.

From commons to commoning

For most people in London living on a median income, the market must seem fairly dysfunctional: the housing market puts homes beyond their reach, while the highly competitive, open labour market keeps their wages in check. At a national level, the market seems to be delivering low growth, rising inequality, stagnant incomes and high levels of debt. Meanwhile, the state seems increasingly distant, its resources heavily constrained, focusing only on essential services. Democracy, both local and national, seems largely impotent in the face of global forces.

If these are the conditions that will determine the lives of many people in London for the next 30 years, then the commons – shared, self-managed productive resources, which allow many people to come together to achieve diverse ends – is precisely what they will need. Far from being a throwback to a bygone age, London’s commons should be an inspiration for the future of the city as a whole.

The classic story of how the commons work has been told by the Nobel Prize-winning economist Elinor Ostrom, who looked at how farmers and fishermen managed common pools of resources, like fish and water. Ostrom found that the commons usually consisted of three ingredients: a shared, usually constrained resource, like a piece of grazing land; a community of users brought together by the need to use the resource; and norms and rules that allow people to monitor one another’s usage to ensure fairness. The commons needs a community of users, or commoners, and a process of management. David Harvey, the prolific urban theorist, calls this process commoning.

A commons only prospers if the commoners do quite a lot of commoning. My prediction is that people are going to want to do a lot more commoning of more aspects of city life in future, simply because this will offer the best way for them to live successfully. One expression of that will be new kinds of green spaces – community gardens and urban farms, guerrilla gardens and pocket parks – which could provide inspiration for other kinds of commons, in housing, health, culture, food and knowledge.

Physical commons matter to urban dwellers because of how we behave with one another when we are in them. The social relations we create in these spaces can then create intangible benefits in terms of the atmosphere and social networks of the city, which in turn feed knowledge, ideas and creativity.

Cities only work if they are places where different people are thrown together and start to get on. As Louis Wirth put it in his 1938 essay Urbanism as a Way of Life, the city ‘has brought people together from the ends of the earth because they are different, so useful to one another, rather than because they are homogeneous and like-minded.’ Common spaces such as parks are one place where we learn to be at ease with difference and take our cues from one another. The most important social contract in a modern, diverse, fluid city like London is the contract between citizens: how we govern one another’s behaviour. Here small acts of reciprocal civility count for a lot. The fact that most dog owners now pick up their dog’s poo is a small example of how norms of civility spread through public spaces. As the state retreats from our lives, we will need more of these kinds of solution.

The city thrives when, as Harvey puts it, ‘people of all sorts and classes mingle, however reluctantly and antagonistically, to produce a common if perpetually changing and transitory life.’ For most of us, most of the time, the social contract with our fellow citizens is far more important than the abstract contract we have with a distant state that is increasingly confined to delivering rationed services. Government may help to create those spaces where we learn collective self-governance, but it cannot provide them.

These common spaces, however, will thrive only if they embrace the pluralism of the original commons.

In my own local green space, Highbury Fields, there are leisure facilities and tennis courts run by sub-contractors commissioned by the council; cafes where people of all sorts gather to chat; self-employed personal trainers and tennis coaches; ice cream vans and children’s crèches; dog walkers, both paid and voluntary; children’s parties and company awaydays. On summer evenings, the Fields turns into an encampment of hipster barbecues with ingredients bought from local shops. Neatly-assembled piles of rubbish are cleared up the next day by the council.

Successful commons are not a drain on the private economy of a modern, creative city: they are central to it. Cities thrive on what emerges from people mixing in unplanned ways. An entirely enclosed, pre-progammed city, regimented by regulations, made homogeneous by wealth, would quickly become dull and boring. When people congregate around common amenities, like parks and markets, places become more economically dynamic and so valuable. Enlightened developers already realise that creating a commons turns out to be the first step to creating a vibrant market.

Fifteen years ago, London Fields in Hackney on a weekend morning could feel like a fairly desolate, neglected place, populated by a few people walking their dogs around a space dominated by some ill-kempt asphalt football pitches with weeds sprouting in the centre circle. Now London Fields acts as a parade ground for an army of young people. In one corner is a lovingly restored lido, brought back to life through a combination of community campaigning and council investment; in another is a pub which spills out onto the park and provides a home for the local cricket team; over the road is Broadway Market with its Australian- or Greek-run cafes, bookshops and artisan butchers.

Successful cities should be a constant interplay between the commons and the market. If the market gets too strong, it will tend to self-destructive excess, killing off the very social capital and common resources it needs to sustain itself. Cities that fragment into mutually uncomprehending private enclaves are a nightmare. Successful cities need a common life to which people feel they belong. London needs, at every level, to look after the commons.

The historic commons can inspire us to see the city differently. But we should aim to do much more than that. Philadelphia is raising a $500m bond to invest in new civic spaces. London is five times larger than Philadelphia, with still-rising property prices, a massive financial services industry and inflows of foreign investment. London should create a new commons fund, worth say, £2.5bn, to create a new generation of common resources, large and small. Public land and assets – the NHS estate for example – should wherever possible be turned into commons. Private property developers should be encouraged and, where necessary, compelled to follow the lead of developments like Kings Cross that put playful public spaces at their heart. We need commons-based, shared, low-cost models combining housing, work and care for young people to live and work together in creative communities; for families to draw on shared child care, education and play facilities; and for older people to be part of multi-generational communities. London will only be a successful, human city in the future if more of us, more of the time, learn to live like common people.