How can a town grow its own high street, with little or no help from outside? A century ago that would have been a strange question: every town's high street had grown more or less organically and was an expression of the industry and resources of the locality.
Today most high street experts - and there are a dazzling variety of them - will talk about attracting investment, getting the offer and the technology right, and persuading retailers and property developers to provide the multi-million-pound deal that will push the high streets of Nether Bogthorpe or Dullsville up the retail rankings.
The story of Incredible Edible Todmorden is familiar to many, but media coverage would suggest it's just a rather quirky community growing project. I think it's much more than that: it gives us important clues about how we can rethink the places we live in.
Incredible Edible isn't a response to high street decline, but to climate change and the absurdities and dangers of a globalised food system. But it matters for the high street: partly because high streets are still important economic and food distribution hubs, and even more because it shows what can be achieved through the power of small actions.
Incredible Edible has understood that to change behaviour, you have to stop telling people what they or others should do, and start showing how change can begin to happen.
Change begins with connections. Creating points of contact; sharing food and skills; making spaces for conversation. That's why the 'propaganda planting' of public places and front gardens works: it creates a place where ideas can be discussed and can begin to change. There's plenty there that is relevant to the future of our high streets.
Incredible Edible has three strands: community, learning, and business. All three matter and are intertwined. From community comes conversation and the human connections that shift behaviour. From learning comes the acquisition of skills and knowledge and, as importantly, the confidence to change. And business grows both out of community and learning, and back into them, reinforcing relationships and understanding.
This is why approaches that begin with business and stress the bottom line above all else fail. They emphasise the fickleness of consumer choice and the importance of the immediate offer, rather than the long term links that build trust. It's those long term links that matter for our high streets, because any online or out-of-town business on some anonymous business park can come up with a more immediately tempting offer or a cheaper price.
A better future for our towns is as places of participation; places where we stop thinking of ourselves only as customers and begin to act as citizens. Instead of droning on about footfall and retail spend, let's measure our towns by their ability to function as good places to live and spend time in.
I like to picture a successful town as a garden, a promenade and a stage. A garden is a place of relaxation and restoration, one that is good for physical and mental wellbeing and enjoyable to be in. The best towns and cities have public parks and green spaces, large and small, at their heart. Todmorden's vegetable growing, in confined spaces like canal-sides or uninspiring places like a health centre car park, changes the look and feel of the town. Eric Pickles thinks the way to save our high streets is through more parking. He'd be wiser to think about more parks.
A promenade is a place designed for strolling, for spending time and taking in the sights and sounds. Create high streets that are walkable and full of interest and people will want to spend time there. Todmorden's Green Route is a walking route, slowing down the pace and providing a sense of unity in a town dominated by major roads.
A stage is a place of possibility - not just a place for spectators but one for performers. When we think of our town centres as stages we create a mental map of possibilities - spaces and places where drama and interaction can occur. Markets are natural performance spaces; so too are parks and paved areas. When a group of people act in a public space, even by doing something as simple as planting vegetables, they are performing and creating an opportunity for the performers to interact with an audience.
The possibility that Incredible Edible opens up is to create high streets that change our thinking instead of dulling it, and feed our souls rather than our habits. Talk to people in the property and retail industries and they'll probably tell you that's pie in the sky. Talk to people in Todmorden and they'll tell you it could be pie on the plate.
• There's more here on the forthcoming book telling the story of Incredible Edible Todmorden.