The acclaimed Norwegian novelist Karl Ove Knausgaard has defended writers who “run up against the limit of what cannot, shall not, should not or must not be written”, arguing that every time an author “refuses to shy away”, the arbitrary nature of such limits is revealed.

In the wake of attacks in France which have left the country reeling, Knausgaard has described freedom of expression as “a paradoxical and complicated right”, because “by permitting that which cannot, shall not, should not or must not be said, it permits that which is evil, bad, subversive, which destroys what we stand for and what we wish to be”.

Knausgaard was giving a keynote speech at Thursday’s Oxfam Novib/PEN awards in The Hague, celebrating four writers – Libyan writer and journalist Razan al-Maghrabi, Iranian journalist and women’s rights activist Jila Bani-Yaghoub, her husband, fellow journalist Bahman Ahmadi-Amouee, and Sudanese poet, writer and journalist Abdelmoneim Rahama – for defending freedom of expression despite the danger to their own lives.

Knausgaard’s speech, translated from Norwegian by Ingvild Burkey, laid out his belief that “the core of the problem surrounding freedom of expression generally and the Paris massacre specifically, has to do with what I call the We”.

“It is within the We that morality is established and enforced, it is the We that determines what can and cannot be said, it is the We that erects the invisible wall, felt by each and everyone when the boundary is transgressed and the consequences, which are social by their very nature, become apparent,” he said. “When the offices of the Paris magazine were attacked and the twelve people who were working there were killed, the act was carried out by men who stood on the outside of this We, and who didn’t identify with it.”

“And when you don’t identify with the We, when you don’t feel that you are a part of its community, then its morals and ideals do not apply to you. If you are outside the identity of the greater community, then you establish your own, in this case that of radical Islam.”

Knausgaard’s bestselling series, My Struggle, controversially takes its title from Adolf Hitler’s memoir, Mein Kampf. The novelist used the work to show how the values a society rests upon can alter. “When Mein Kampf was published in Germany in 1926, it was ridiculed in all the major newspapers. It was considered inferior, vulgar and unintelligent ... A mere ten years later a whole new society was being built up around the same book and its values,” he told his audience, revealing that when he set out to read the work on a plane, he found he couldn’t take it out of his bag.

Morality changes, he said, and a morality which “presupposes a We” is dangerous. “Every time a writer refuses to shy away when he or she runs up against the invisible wall, but instead overcomes internal and external resistance, then both the one and the many become visible, the boundaries are exposed, and their element of arbitrariness become apparent,” said the novelist. “Only then can the We, its morality and values be renegotiated, and another identity become possible.”

Knausgaard also used his speech to honour the evening’s four winning writers’ “incomprehensible courage”. “The courage it takes to speak out against totalitarian or fundamentalist power, knowing full well the possible personal consequences of doing so, is beyond comprehension,” he said. “All of them are writers, journalists and activists who have been persecuted for their opinions and expressions, and who have been willing to pay an indescribably high price for what they believe in.”

The only writer present at the event, al-Maghrabi, has been critical of religious extremism and is “regularly harassed” on the street, living in fear of attack, kidnap or arrest, according to PEN International. Bani-Yaghoub, editor of a women’s rights website, served a one-year prison sentence and was given a 30-year ban on being a journalist, over charges including “insulting the president”. Her husband Ahmadi-Amouee, editor at the business daily Sarmayeh, was given a five-year prison sentence, convicted of charges including “gathering and colluding with intent to harm national security” and “spreading propaganda against the system”.

Rahama, co-founder of the opposition daily newspaper Ajras al-Hurriya (Bells of Freedom), was arrested in 2011, tried and sentenced to death. A year later he was released, and left Sudan for Ethiopia in March 2013.

The awards, said PEN International’s Carles Torner, were not only intended to honour the recipients for their courage, but are also “a way of telling those who seek to silence them that the world is watching”.