I remember hearing a successful musician being interviewed and he was asked whether the key to his band's success had been inspiration or effort. His response was that success had been 90% perspiration and 10% inspiration. We could argue about the percentages but the same principle holds whether we are talking about musicians, writers or, indeed, pretty much any endeavour that a person might choose to embark upon. If you are an entrepreneur, having that spark of inspiration for a new product is vital but to get that product to market and then achieve a profit will take a whole lot more time and effort. This analogy works equally well for a writer who wants to become a novelist.
Let's take the example of a novel to expand upon the premise that effort is more important than insight. At the outset, I want to make it clear that no-one doubts that inspiration plays a vital role in the creation of a quality novel. Great writers, such as Philip Pullman, Stephen King, Douglas Coupland, etc, undoubtedly have a surfeit of insight and inspiration and this enables them to write novels that stand out from the masses of competing books that populate book store shelves. However, coming up with a great story idea or an innovative plot is useless unless the writer has the discipline to sit down day after day and type out thousands of words to turn their initial inspiration into something that is material and which can earn them a living.
The aspects of writing that rely on insight are the glamorous part of writing. They are what make us wish that we could give up the day job and live the life of a writer. What most of us don't see is the unglamorous side. Authors frequently talk about the sacrifices that they have to make to indulge their chosen profession. They give up going out at the weekend, or spending time with their kids. Whilst the writing process is ongoing, they may become grumpy virtual recluses with heavy bags under their eyes and possessed by an alarming addition to coffee! That's not to say that the process of writing can't be fun. Terry Pratchett once commented that writing is the most fun thing that you can do on your own. However, it's not always fun and there are countless times when writers have to force themselves to persist, even though all they really want to do is chuck their half-completed script in the bin.
Another indication of the importance of effort is the number of would-be-writers who believe that they have a novel within them but have never been able to get it out of them and down onto paper. Writing the first 5,000 words or so may prove plain-sailing as they freewheel on that initial adrenalin surge that follows the inspiration stage. However, the prospect of having to extend the novel to around 100,000 words often becomes daunting and many writers fall by the wayside. They may have the technical skills to write to a high standard but it's only those who are tenacious that tend to complete projects (and complete them on time), which is a critical attribute if a publishing house is going to engage in an ongoing relationship with you.
So far, this article has been written mainly from the perspective of my own view on whether writers rely more on inspiration or effort. However, it's probably useful to get a flavour of what actual authors have said on this topic. Thanks to the magic of the Internet, I was able to discover some author quotes on the topic of inspiration. As you'll see they're all fairly disparaging on its importance!
"I can't explain inspiration. A writer is either compelled to write or not. And if I waited for inspiration I wouldn't really be a writer." (Toni Morrison, quoted in Time magazine, January 21, 1998)
"Had I mentioned to someone around 1795 that I planned to write, anyone with any sense would have told me to write for two hours every day, with or without inspiration. Their advice would have enabled me to benefit from the ten years of my life I totally wasted waiting for inspiration."
(Stendhal [Marie-Henri Beyle], quoted by Enrique Vila-Matas in Bartleby & Co, New Directions, 2004)
"You can't rely on inspiration. I don't even believe in inspiration. I just believe in working. Work generates work. What frustrates me horribly is not knowing what I'm going to do next. And so you force something to happen. . . . You can't sit around thinking. You have to sit around working."
(David Long, interviewed by Linda B. Swanson-Davies in The Glimmer Train Guide to Writing Fiction: Inspiration and Discipline, Writers Digest Books, 2007)
(Acknowledgement: All the above quotes are taken from "Writers on Writing: The Myth of Inspiration", an online article by Richard Nordquist. His full article can be found at http://grammar.about.com/od/advicefromthepros/a/Writ ersInspiration.htm and is worth reading in full)
To conclude, then, inspiration and insight are tools that writers can use but should certainly not rely upon. Indeed, where it does arrive, inspiration often follows long hours of graft. It is effort and self discipline that are the attributes that most successful writers value highest. The bottom line is that there are lots of people who can write to a technically high standard but very few are able (or prepared) to devote themselves to the long lonely hours that are required to plan, write and edit a novel.
Sources:
http://grammar.about.com/od/advicefromthepros/a/Writ ersInspiration.htm