Forgiveness is a principle promoted by just about every faith tradition. Even neuroscientists agree on its mental and physical benefits — from lowered risk of heart attacks to improved sleep. And yet the concept of forgiveness can stoke controversy, even anger.

Twenty years ago, UK-based journalist Marina Cantacuzino launched the Forgiveness Project, a collection of stories from survivors and victims of crime and conflict, as well as perpetrators who reshaped their aggression into a force for peace. Now in Minneapolis as part of her Midwest book tour, Cantacuzino is continuing to share those stories in the hopes of spreading a shared understanding of humanity.

But even Cantacuzino was unprepared for how much she had to learn.

"I started with this impression that forgiveness was a magical space where everything could be fixed and resolved, a panacea for all ills," Cantacuzino says. "Very quickly I was disillusioned of that naïve view. I realized it was complex, messy, complicated and meant many things to many people."

She still believes in the transformative power of forgiveness, even though she knows it can't be foisted upon anyone, and in some circumstances it can do actual harm.

Over the years, Cantacuzino documented real-life stories of seemingly supernatural examples of forgiveness. A Canadian woman who forgave her husband's killer. An Israeli filmmaker wounded in a terrorist attack. A Minneapolis mother who grew to love the person who murdered her only child. That woman, Mary Johnson-Roy, passed away last month, and loved ones recently celebrated a life that inspired mercy and healing.

A single act of forgiveness can mystify, sometimes enrage, those who witness it. The Forgiveness Project's exhibit curator for North America, Louisa Hext of Minneapolis, summoned to mind a story about her late friend Eva Kor. "Forgiveness is my chemotherapy," Kor, a Holocaust survivor, would often say.

Kor and her sister were part of the thousands of twins experimented on at the Auschwitz concentration camp in German-occupied Poland. Kor's parents and older sisters were killed in gas chambers at Birkenau.

Years ago, Hext invited Kor to speak at a synagogue in Chicago, where another Auschwitz survivor, also in her 80s, shamed Kor in front of the entire congregation for offering forgiveness to the Nazis. After the talk and the crowd began to disperse, Kor invited the woman to come up and sit by her. Kor told the woman, "I love you."

"How could you love me?" the woman responded.

"We're survivors," said Kor.

"There was no reconciliation," Hext says, "but there was empathy and at least a willingness to come together, and with civility, hear the other person's story."

Kor's ability to forgive her oppressors was not a sudden, radical act, Hext explains, but the end of a long personal journey to transform her life and recover. As the late Nobel peace laureate and archbishop Desmond Tutu once told Cantacuzino, "To forgive is not just to be altruistic. It is the best form of self-interest."

But even Cantacuzino admits it can seem difficult to relate to those who forgive the seemingly unforgivable. Are they morally superior? Extremely religious? Some are, but they are more likely to share the traits of curiosity, empathy and a flexible viewpoint.

It feels like those characteristics are harder to come by today. The cacophony of "if you're not with us, you're against us" has divided families and entire communities. One's ability to recognize the pain on both sides of the Israel-Hamas war can evoke outrage, for example. But Cantacuzino continues to support discussions that bring together Israeli and Palestinian victims of the conflict, stories that require people to embrace complexity and contradiction while honoring the "sanctity of every human life," she says.

The Forgiveness Project's exhibit has now journeyed to 17 countries, including Kenya, Australia and Israel. Consisting of cloth banners bearing photographs and text, it's on display at University Baptist Church, 1219 University Av. SE., Mpls., until Friday. (Johnson-Roy's narrative is not included in this exhibit, but it's featured on the Forgiveness Project's website. At startribune.com, you can also read a moving tribute to her life by my colleague Matt McKinney and a column I wrote last year about her struggle with Lewy body dementia.)

Cantacuzino will also appear for a book reading at 2 p.m. on April 28 at Big Hill Books, 405 Penn Av. S., Mpls. Her latest book is called "Forgiveness: An Exploration." It delves into the politics, mechanics and psychology of forgiveness. But still at its heart are the stories.

She got no argument from me when she preached the power of narrative. "Stories stick, whereas facts fade," she says.

We need these stories now more than ever.