“If what I’m writing is not useful, I stop.” Speaking via video link to an audience gathered in Mantua’s Piazza Castello, American Pulitzer prize-winning novelist, short story writer and activist Alice Walker, explained her philosophy on writing.

Walker’s writing tackles strong, controversial, often violent themes, such as segregation and domestic violence. “It takes a great deal of tolerance, patience and compassion to struggle with these characters,” she said. But feeling the suffering of others means you have a soul, and this sense of internal empathy and integrity is vital. “When you lose your soul, you end up with a planet in crisis.”

“If we want to transform the world – and we must – we have to change ourselves,” said Walker. She cited the character Meridian from her 1976 novel of the same name, who becomes involved in struggles she initially does not comprehend. She feels people are being harmed, and she reacts. Personal transformation can be a lonely struggle, the author noted.

As well as urging for change through her own writing, Walker has been instrumental in reviving interest in other black American writers, such as Zora Neale Hurston, and these days African American writing, including by women, is more widely appreciated. “There has been a beautiful flowering of women of colour writers. We need this, like soil.”

She talked about being encouraged by James Baldwin’s success. As an 18-year-old college student, she took the bus north to work over the summer. Arriving in Boston, she found an entire rack of Another Country in the bus station bookshop. Up until that point, she had not imagined that black writers could sell books.

But we do not have to be award-winning novelists to be agents of change. What’s important is to decide what we can commit to, and follow through with that. “Doing nothing is the only thing that will defeat us.”

The author excused herself to let out her dog, who was barking, returning to answer questions from the audience on other writers she admires. There are plenty, many of them reviewed on her blog Alice Walker’s Garden. She had reviewed an outstanding book by an Italian author, she said, whose name she didn’t recall. It turned out to be Elena Ferrante’s The Days of Abandonment, “a universal story”. The audience appreciated her account of the story: “A woman whose husband leaves her; she goes to pieces, but the children don’t care.”