Novelist Haruki Murakami on Sunday warned against excluding outsiders and rewriting history during his acceptance speech at Denmark’s Hans Christian Andersen Literature Award for 2016.

“No matter how high a wall we build to keep intruders out, no matter how strictly we exclude outsiders, no matter how much we rewrite history to suit us, we just end up damaging and hurting ourselves,” he said.

The 67-year-old author did not specify what he meant by “wall” or “outsiders,” but he may have been referencing the increase in anti-refugee and anti-immigrant sentiment in Europe and other parts of the world.

Murakami, one of Japan’s best-known contemporary novelists and who is often touted as a candidate for the Nobel Prize in literature, has been vocal in the past about his thoughts on social issues, such as Japan’s dependence on nuclear power.

His speech, delivered in English, was titled “The Meaning of Shadows,” after Andersen’s “The Shadow.”

He said that just like individuals, societies and nations have shadows to be confronted.

Murakami, who only recently read “The Shadow,” said he “had no idea at all” that the Danish author wrote “such a dark and hopeless story.” The story is about a scholar who is eventually taken over by his shadow and murdered.

“It’s not just individuals who need to face their shadows. The same act is necessary for societies and nations. Just as all people have shadows, every society and nation, too, has its own shadows,” he said. “If there are bright, shining aspects, there should be a counterbalancing dark side.”

Murakami went on: “You have to patiently learn to live together with your shadows. Sometimes in a deep place you have to confront your own dark side.

“It is a necessary thing to do, because if you don’t, before long your shadow will grow ever stronger and will return, some night, to knock at the door of your house. ‘I’m back,’ it’ll whisper to you,” he said.

Murakami recounted that when writing a novel, which he described as a “journey of discovery,” he at times encounters “a totally unexpected vision of myself, which must be my shadow.” He said his role as an author is to “portray this shadow” in a candid manner, accept it as part of himself, and share this with readers.

He said that people must face their own shadows, confront and even work with them, because not doing so will impede growth and maturity.

In the worst case, he added, people could end up being “destroyed by their own shadows,” as happens to the main character in Andersen’s tale.

When the award committee members selected Murakami last November as the winner for 2016, they said his “capacity to boldly mix classic narrative art, pop culture, Japanese tradition, dreamlike realism and philosophical discussion makes him a fitting heir to the Andersen legacy.”

Previous winners of the award include J.K. Rowling, known for the “Harry Potter” series, and Salman Rushdie, author of “Midnight’s Children” and “The Satanic Verses.”

The award carries a total of 500,000 kroner ($73,800) in prize money.

Murakami’s works, including “1Q84,” “Kafka on the Shore” and “Norwegian Wood,” have sold millions of copies and have also been translated into numerous languages.