Rebecca, this is a kindred spirit in many ways. There’s a ton of good advice in this thread alone, worthy of making this thread a “keeper” of many sorts.
However, I have to add my two cents to your dilemma. I’ve written a dissertation in engineering way back when and I’ve since gone to law school, clerked in an appellate court and litigated and later written much. Lawyer jokes aside, nonfiction writing and I are suitably acquainted.
That said, when I venture outside of my competence and apply my research skills in other areas, I nearly always run into the problem you’re describing… Why? Because the research is so fascinating! Because there is so little time for it, and because I am writing in an area in which I am not “established” as I am after defending a thesis and after advancing my legal writing, even in the face of old experienced crusty judges. That experience of having my work in engineering and legal writing has solidified my confidence in writing there.
When it comes to one work I’ve had in project form for 13 years or more… Yes, 13 years, I am timid.
I like the research. I discuss sub topics with numerous others. I chase rabbit tracks down rabbit holes that open fascinating new doors. I write little things here and there. But, recently I realized the difference as to why I wasn’t able to whip up a good 30 page succinct thesis on any of it the way I can about legal topics I’ve never studied until the question arose – namely, my project had no purpose-- that is to say, no focal point on which to write. Instead, I am enjoying the learning and finding things to say along the way. In legal work, I am answering a question or questions. My dissertation had a narrow focus on Monte Carlo gaming simulations and chemical process simulation in finite element computations. There was a point at which I could say I answered the question, and rewrite and rewrite to better answer the question.
My realization lead me to define a focus for my project such that I could write on it and head towards a goal even though I leave a lot of open threads to write on next. It’s OK. With as much passion as this project has given me and as entertaining and fun I find the research, it’s no good sitting in my DTPO and hard files… It needs to be shared in a more general format than with the few minds I am lucky enough with whom to have email, telephone, and lunch conversations.
For this focus, Druid’s series of questions are near identical to what I thought to do to myself last winter and have been working on now. Do what he suggests and narrow your writing job down to that question or pressing need to your work. Then you can write.
Don’t worry about the loose ends! Don’t worry about what else is developing. Your project sounds like mine in as much as you’ve probably already compiled an encyclopedia of research and are always interested in further cultivating it and improving it. Let’s face it, that’s fun!
But face this, too, it’s not doing any good sitting in your mind.
From what you mentioned earlier, and synthesizing Druid’s questions, try these:
Why does everyone argue about X and miss this obvious point?
How would the discussion change with your point?
Give 3 examples from each side of the point showing how people danced around your theory.
Give 3 examples (no more) of discussions that would be forever changed based on your point.
Describe the oddest thing that will change (in your perspective).
Describe your expectations of the discussion now that your point is made.
Now, with the kind of research you’ve mentioned, if we are dealing with similar projects, you’ve wanted to get into all the fine detail you see around things… Save it for the speech tour. Save it for the next book. Save it for the interviews and articles. It makes for intersting discussion beyond the book itself.
It’s the focus of your writing task that you’re missing. Right now, you are writing an encyclopedia. A noble endeavor, but not for someone who works 17 hours a day. You need a narrow focus in order to see the writing tasks to get you to a published point. I hope my two cents here help you find that.