Now that I am offering editing to independent authors, here are some thoughts about what I think you should expect from a literary editor. Part 1 is about editing and editors. Part 2 will be about what services I think an editor should provide, and what you should expect your editor to do with your text.
Part 1: What makes an Editor
What is a Good Book? I'm sure the reply is pretty much unanimous: a good book is subjective, personal. But just as I can tell a good violinist from a bad one, although I know nothing about playing the violin, so most people can recognize a bad book. So can most people be editors? I don't think so. Most people can be proofreaders*, however.
Who is a good editor? Derek Prior and I both studied drama theory, and in the course of our studies learned the craft of textual analysis. Textual analysis arises on the one hand from the kind of literary criticism developed by F. R. Leavis and his contemporaries, and on the other hand from the desire to apply scientific rigour to the study of literature. I have applied textual analysis in every type of work and writing that I have done**. A good editor needs to be able to combine his analytic skill with a deep understanding of what makes a story work.
What makes a story work? This is not as hard to pin down as what makes a good book, because what makes a story work is contextual rather than subjective. I have read manuscripts that contain no story - just a series of related events. Sometimes this results from the naturalistic fallacy (that I will discuss another time), sometimes just from narrative incompetence. Narrative incompetence is the inability to tell a story. As long as your manuscript features a story, your story can be made to work. How to make it work means getting down to the nuts and bolts of narrative mechanics, and putting right what is obviously wrong. Sometimes an editor's work is limited to this, but this alone does not make a good editor.
So what makes a good editor? A good editor needs to know what makes a good writer. After all, an editor needs clients, and a client who is a good writer will be good publicity for an editor. So a good editor will be able to show a writer not only how to improve his book, but how to become a better writer.
* The techie culture surrounding indie publishing has made "beta-reader" the favoured term. Literally, 'proof read' means 'test read'. A proofreader is someone who reads as if they are the intended reader, whether for pleasure, information, study, who is able so state, thereafter, whether the book met their need.
** In French academia, there is a vast, rich, and mostly redundant vocabulary of technical terms that can be applied in textual analysis. I try to steer clear of this kind of thing, though some of the terms are indispensable.