Over the last decade, we have become better at knowing what brings us contentment, well-being and joy. We know, for example, that there are a few core truths to science of happiness. We know that being kind and altruistic makes us happy, that turning off devices, talking to people, forging relationships, living with meaning and delving into the concerns of others offer our best chance at achieving happiness. But how do we retain happiness? It often slips out of our hands as quickly as we find it. So, when we are exposed to, or learn, good things, how do we continue to burn with them?

And more than that, when our world goes dark, when we're overwhelmed by illness or heartbreak, loss or pain, how do we survive, stay alive or even bloom? In the muck and grit of a daily existence full of disappointments and a disturbing lack of control over many of the things that matter most - finite relationships, fragile health, fraying economies, a planet in peril - how do we find, nurture and carry our own inner, living light - a light to ward off the darkness?