Self-doubt feeds the author. Without self-doubt, we don't strive to do our best --- to keep writing despite rejections and humiliations. (See Dean Koontz, for example, who writes: "I have more self-doubt than any writer I’ve ever known. That is one reason I revise every page to the point of absurdity! The positive aspect of self-doubt – if you can channel it into useful activity instead of being paralyzed by it – is that by the time you reach the end of a novel, you know precisely why you made every decision in the narrative, the multiple purposes of every metaphor and image. Having been your own hardest critic you still have dreams but not illusions."). Self-doubt is what propels us to be better, to write better, to fixate on commas and words that most other people ignore.Writers have a pretty unique challenge.
On the one hand you have to have the confidence to spend and hours at something without really knowing how it's going to turn out, and often without knowing whether you really have the talent or the right idea to execute a story that people are going to love. It takes fortitude, commitment, and a deep confidence that what you're doing is worth it.
On the other hand, you have to have the self-doubt to be critical enough of your own work to make it better. You have to turn a cold eye to your writing to spot flaws and weak spots, to know your own weaknesses, to improve on them, and not get carried away.
These impulses seem contradictory, but I'd actually argue that they're two sides of the same coin: It's all confidence.
To be able to spot your own flaws requires confidence. Staring your own weaknesses and flaws in the face doesn't come from a place of self-doubt, it comes from a place of strength. You have to be a strong person in order to own up to your flaws and to shoulder the responsibility of making your work better.
There are some writers out there who seem so boldly confident and brash, but it's really a mask. When someone suffers from supreme overconfidence and can't see their own flaws, in truth they're not confident at all. They lack the strength to admit their own shortcomings. We all have flaws, but not everyone has the strength to confront them.
And on the flip side, it's important not to overdo the self-doubt and paralyze yourself with indecision either. It's easy to despair that you're not good enough, that you'll never get there, and to magnify the weaknesses in your writing, especially when you're just beginning. That too is what happens when you are approaching writing with insufficient confidence.
The only way to strike the right balance as a writer it is if you build up your confidence in a healthy, clear-headed way.
Confidence will give you the strength to doubt yourself.
Art: Doubts by Henrietta Rae