Brenda Ueland:

...I have come to think that the only way to become a better writer is to become a better person. By better I do not mean goody-goodier, for a great person often does things that so-called good people think very bad indeed. And I have come to think there is irony in the lives of writers who sit at a desk always, tenderly or crossly protecting themselves from all disturbances, danger or uncomfortableness, so that they can work out a better literary style.

If You Want to Write, p. 129-130