Harper Lee’s “Go Set a Watchman” brings to mind Fyodor Dostoevsky’s observation that, if asked not to think of a polar bear, it would be impossible to think of anything else. The same is just as true of elephants as it is polar bears.

Of course, the elephant in this literary room is “To Kill a Mockingbird.”

One can’t read “Go Set a Watchman” except through the lens of Lee’s masterpiece. This would be true even if its major characters — Jean Louise “Scout” Finch and her father, Atticus — weren’t in both books, along with several other characters. This would be true even if “Watchman” wasn’t rejected before the publisher urged Lee to rewrite it from Scout’s perspective as a child rather than an adult.

“To Kill a Mockingbird” is that good. “Go Set a Watchman” is not its equal, and that is why it wasn’t published in the 1950s. But that is not to say it isn’t worth reading.

Lee’s recently released book gives “To Kill a Mockingbird” fans an incredibly rare look into the process of writing a great work, and the development of the author who produced it. For that alone — and regardless of how she depicts Atticus Finch — we should be grateful.

Lee’s growth as a writer and the editing that made her first book a beloved classic is missing in a number of ways in “Watchman,” beginning with the train ride that opens the book and serves as little more than 20 paragraphs of throat-clearing before she begins the actual story. She drops in an annoying number of obscure references, especially having written it in an era when readers couldn’t pull out their smartphones and Google them.

Some of the dialogue — especially her climactic encounter with Atticus — is unrealistically perfect, requiring erudition that would tax the ability of even the most polished, prepared debaters. The conversations in “Mockingbird” were more believable.

And the book’s conclusion is not nearly as satisfying.

That said, Lee’s eye and ear for the sights and language of the mid-20th century Deep South remain wonderful. In addition to the compelling story, much of what made “Mockingbird” so beloved was how Lee transported the reader to this small town in rural, Depression-era Alabama, with characters who cast a shadow across the page.

No one should be surprised that Jean Louise Finch grew up to become a sassy adult, whose observations on the people and situations she encountered were pointed and often hilarious.

“Watchman” includes some flashbacks to her childhood and characters like her brother, Jem (now deceased, as is revealed in the first chapter) and Dill Harris.

There are even references to Atticus having once courageously served as attorney for a black man falsely accused of rape. The seeds of “Mockingbird” are scattered throughout this book.

One of those seeds, however, grew in an unexpected way.

Given the news coverage, it’s not much of a spoiler to reveal that the Atticus Finch of “Watchman” has racial attitudes at odds with his “Mockingbird” persona. But this is a different book.

In “Mockingbird,” a young girl found a hero in her father. In “Watchman,” a grown woman learns her hero has feet of clay.

This Atticus Finch, like countless old white men in the South, struggled to deal with a civil rights era that shook the assumptions that surrounded their existence. One can envision a white attorney of that era who refused to allow a black man to be unfairly destroyed, yet who had blind spots about racial equality. Such a man is a more realistic representative of this time than the pillar of rectitude that “Mockingbird” presented.

Realism, however, can be overrated. It’s not as good a story.

That is what a publisher thought six decades ago, and we should be thankful. Had “Go Set a Watchman” been published, “To Kill a Mockingbird” would never have been. Reading the former will help you appreciate the latter even more. If that’s possible.