‘A town isn’t a town without a bookstore,’ Neil Gaiman wrote in his 2005 novel American Gods. ‘It may call itself a town, but unless it’s got a bookstore, it knows it’s not foolin’ a soul.’

Salisbury is a city with a longstanding bookselling heritage. Way back in 1773, a guidebook to the area lauded the local booksellers as ‘equal to most in London’. More recently, the city was home to the headquarters of the book chain Ottakar’s, one of those bookselling names that is now sadly part of publishing history.

While publishing has changed immeasurably over the years, what hasn’t is the sheer delight of browsing the shelves of a good bookshop. A good bookshop is made by the people who work in them and here Salisbury is blessed with booksellers like Waterstones’ Jo Boyles, Sarum College Bookshop’s Jenny Monds and Oxfam’s David Taylor: committed, passionate, talented individuals, who know their bookselling onions.

I know just how excellent these booksellers are, because I was once a not-very-good bookseller for Waterstones myself. I was reminded of that chastening experience this week with the release of the film Denial. Written by David Hare, this powerful film tells the story of the libel trial between author Deborah Lipstadt and controversial historian David Irving (played in the film by Rachel Weisz and Timothy Spall respectively). Irving had sued Lipstadt over her book Denying the Holocaust, in which she challenged revisionist accounts of what happened in the Second World War.

While all this was going on, David Irving turned up in the Hampstead branch I was working in to persuade me, as the history buyer, to stock his latest book. Irving was an imposing figure, both literally and intellectually, and my 24-year-old self was out of my depth. I’d like to say that I defeated Irving’s opinions with my own sound philosophical reasoning. Instead, imbued with the confidence of youth, I chose the slightly less subtle comeback of telling him there was no way I was having his books in my shop. The basis for a Hollywood film this was not.

I might have gone about it the wrong way, but the principle behind my actions was right. Because being a good bookseller is about more than just selling books. At their best booksellers are the custodians of our culture, nurturing the next generation of young minds and opening older ones up to fresh thinking and new ideas. You don’t get that from an Amazon algorithm. So the next time you want something to read, remember to support your local bookshops. Because as Neil Gaiman says, a town isn’t a town without one.

Follow Tom on Twitter @bromleyesq