Considering he’s been dead for 40 years, JRR Tolkien has been very busy of late. This summer it was announced that Tolkien’s first work, a novel called The Story of Kullervo, was to be published in August.

The news came just a month after the release of Go Set A Watchman, the surprise sequel to Harper Lee’s classic To Kill A Mockingbird, which shocked audiences by showing the saintly lawyer Atticus Finch as an elderly racist. As if one sequel to Mockingbird wasn’t big enough news, Lee’s estate has now suggested that she may have written a third novel. Presumably they found one of her old typewriters behind the sofa.

The idea of a writer stepping in to take over a late author’s projects is pretty common. Anthony Horowitz seems to be doing a fine job writing new adventures for both Sherlock Holmes and James Bond these days. The difference is that James Bond and Sherlock Holmes never really left the zeitgeist, and have been around for so long, in so many different forms, as to almost be in the public domain. It also helps if you can claim to have the original author’s blessing. Eoin Colfer was hand-picked to finish the Hitchhiker’s Guide to the Galaxy series by Douglas Adams’ widow Jane Belson – a ringing endorsement, if ever there was one.

By contrast, what’s happening with Lee and Tolkien smacks more than a little of opportunism. Harper Lee is an 89 year-old woman, her hearing and eyesight both failing after a stroke in 2007. What sounds more likely – that a celebrated author would go back on a 55-year promise to never publish anything else again, or that a bunch of lawyers convinced a doddery old woman into signing off on a project to make the estate even more lucrative than it already is? As for Tolkien, be honest – as undeniably popular as his writings are, would a new book really be coming out in 2015 were it not for the obscene amount of money brought in by Peter Jackson’s films?

Even putting aside questions of good taste, we have to consider the possibility that these authors let their works remain unpublished for a reason – namely that they were works in progress. Go Set A Watchman is effectively a first draft of To Kill A Mockingbird, and one that Lee’s publishers initially rejected in favour of the focus on Scout Finch’s youth which would form the basis of the book. Similarly, The Story of Kullervo was Tolkien’s first attempt at building a story around a language of his own design, something he would eventually perfect in The Silmarillion and The Lord of the Rings.

Again, there’s a precedent. When Franz Kafka died in relative obscurity in 1924, he gave his unfinished works to his close friend, Max Brod, with instructions that they should be destroyed. Brod ignored his friend’s wishes and went on to publish the works, cementing Kafka’s reputation as one of the greatest writers of the 20th century.

If it worked for Kafka, why not Harper Lee? Apart from the fact that she isn’t dead, Harper Lee was already incredibly well-known when Mockingbird was published. Brod could at least argue that he was helping to give exposure to an unknown artist, but shouting of Harper Lee’s literary brilliance is preaching to the converted.

Not every writer can be as prolific as Franz Kafka. It’s often said that everyone has one great novel in them, but for a lot of people it’s also the only novel they have in them. Now that the hype around Go Set A Watchman has started to die down, critics are admitting that it’s really a pale imitation of its predecessor. I suspect much the same will be said of The Story of Kullervo.

It’s the equivalent of releasing an early cut of Star Wars without the special effects, or taking the Mona Lisa off the wall of the Louvre and replacing it with one of Da Vinci’s early sketches. It’s interesting to see how an artist arrived at the work that made them famous, but the real thing is the real thing.

As someone who adored the Discworld series and was devastated this year by the death of Sir Terry Pratchett, I know how difficult it can be to say goodbye to a beloved author. But all good things must come to an end, and it’s usually a lot better when they stay ended.

Phil Bayles