The early reviews of Go Set a Watchman have focused on the new, “racist”, Atticus Finch. For many readers Harper Lee has trampled over their dreams, reducing a true literary hero to something hateful: a broken, old man filled with barely concealed hatred for the “negroes” he once defended. Some of this is true, but the novel and Lee’s characterisation of Atticus are more subtle than this portrayal.

To Kill a Mockingbird has a special place in people’s imaginations. Many will have first studied it at school. It is that rare thing: a book that has transcended its covers, taking on a powerful, political life. For Oprah Winfrey it has become America’s “national novel”. And unlike some other classics taught at GCSE, Mockingbird has real literary value that can survive the numerous assaults leveled at it by examination boards.

And so it would have been much easier to have not published Go Set a Watchman. Lee could have left us with Atticus, the paragon of white virtue, bravely defending the innocent, black, Tom Robinson. But her decision to add to this narrative, to make it more complex and compelling, is surely one of the bravest acts in modern publishing history. I finished Watchman with renewed respect for Lee, and a more developed understanding of Mockingbird.

However, the newly released book has significant weaknesses: I laboured through the pages dedicated to discussions about Methodist sermons; I am unable to explain why such a gifted writer used so many clichés (teeth are “cut”, various birds are “killed with one stone”, bats invariably fly “out of hell”); and the dialogue is often unconvincing, with conversations drawn out beyond what is needed for the action, or the character.

In terms of technique, the most radical change is that the first-person narrative of Mockingbird has become third-person, although it actually moves between this and free indirect speech. With such an ill-defined relationship between author, main character (Scout) and reader, it is not surprising that the ideas explored are, at times, lacking in coherence. And, of course, there is no narrative climax to rival the trial scene in Mockingbird.

Watchman needed an editor who could have insisted on further rewrites, but Lee is now 89, and almost completely blind and deaf. We will have to take this text, with all its imperfections, as it is. Strictly speaking, Watchman is not a sequel to Mockingbird; it is an early version of Lee’s novel that, on the advice of her then editor, was redrafted over two years. It is set again in Maycomb, Alabama, but much is different: Scout is a 26-year-old woman (who uses her real name, Jean Louise), returning home from New York to see her arthritic, 72-year-old father. It is the mid 1950s, and the Supreme Court’s determination to dismantle segregation in the South is being violently opposed by many whites. Understanding this context is important because it explains - but does not excuse - the resistance that many whites (including Atticus) put up to challenge these reforms.

Like many people who return from the big city to their sleepy first homes, Scout is quick to compare, and even quicker to condemn. Much of the power of the novel is to show us how time changes everything, forcing us to reconsider not only ourselves but also those we are closest to. This search for identity - personal, local, and national - drives the narrative, and provides us with the novel’s most powerful moments.

And, symbolically, it is in the courthouse that the novel’s real momentum begins. There, Scout watches in horror as her father sits, listening (tolerating!) a hate-filled talk given by a “sadist” who warns against greater freedoms being given to black people. After leaving the courthouse, Scout is physically sick, a visceral reaction that is matched by her moral condemnation of everything she has heard. And she turns that hatred on her father in an episode of astonishing power:

“I’ll never forgive you for what you did to me… I believed in you. I looked up to you, Atticus, like I never looked up to anybody in my life and never will again.”

Such words could have been said by everyone who has responded with such anger at Lee’s rewriting of such a loved character. But, like Atticus, she had to do it if she is to reveal greater, less comfortable truths, both about America and what it means to be “human, all too human”. If an author is the parent of her characters then Lee has taken that most difficult, but necessary, step: she has allowed them to grow up. And in doing so she has forced all of us who idealised Scout and Atticus to realise that there are no knights in shining armour (or white suits). There are only human beings. Atticus’s brother says to Scout at the end of the novel:

“He [Atticus] was letting you break your icons one by one. He was letting you reduce him to the status of human being.”

In doing so, Scout finds her own identity, and loves Atticus for what he is: a flawed, imperfect man struggling to come to terms with a changing world, rather than what she wants him to be. Lee has reminded us that it is the writer’s job to reveal truths. She has set Atticus Finch free from the gilded cage of misplaced adulation. We should do the same.