Somehow, for all my outward pretence of cold-eyed professionalism, all my insistence that writing is simply a job like any other, I’ve discovered to my surprise and chagrin that there’s more than that going on around here, that I write as much out of karmic necessity and some inescapable inner need to rededicate my own skills constantly to my — what? My craft? My art? My profession? I wrote these stories because the only way of earning a living I have ever had has been by writing, but mainly, I have to admit, I wrote these stories because I couldn’t not write them. Well, so be it. They involved me in a lot of hard work, but for me, at least, the results justify the toil. I’m glad I wrote them. Writing them, it turns out, was important for me, and even pleasurable, in a curiously complex after-the-fact kind of way. May they give you pleasure now too.
— Robert Silverberg, from his Introduction