Some advice on writing the prospectus
As Gerald Graff says, the basic structure for a scholarly piece is “They say; I say.” That’s pretty much the bulk of a prospectus (one part is the “how you will say it”). So, to write a prospectus, you can start with either part. If you’re clear on what you want to say, write that first; then try to figure out how what you’re saying fits with existing scholarship. If you aren’t sure just what you want to say, then starting with the existing scholarship can get you going.
What follows is some very specific advice that is intended to get you going on your writing. Like all such advice, you should abandon it the second that you start to write on your own–this is the training wheel version of writing your prospectus.
Loosely, the “thesis” for your prospectus will probably have the form of “Looking at W text(s) in X way will change Y disciplinary conversation in Z way.” (Not that there will be a sentence anywhere in your prospectus that has that form, but that you might find that way of framing your project will help you write the various parts when you get stuck.)
In my experience, students are really clear on one of those terms before they start the project–in fact, that’s what makes them interested in doing it–but not on the rest. And that’s fine. So, you might start by writing about whatever term seems clear (or strongly motivating) to you. You must start writing before you’re clear on all of them (and keep in mind that every term might change between your prospectus and your final dissertation, so don’t expect that you’ll ever be certain on each term).
Also keep in mind that you’re talking about trying to change a scholarly conversation–not end it. You change it by:
• complicating a crucial term (subjectivity), narrative (current-traditional rhetoric was refinement of belles-lettres), or evaluation (current-traditional rhetoric was oppressive). [Introducing a new term usually operates by showing that an existing understanding is inadequate, so that’s in this same category.]
• confirming one side in a scholarly debate (it’s fairly unusual for students to do this, and, I think, limited to people doing quantitative or archival research).
• forwarding a new definition of a crucial term, new narrative, or new evaluation, or proposing a new way of doing things.
Students often think that they need to do the third, but that can only be done if you do the first, so it’s probably wisest to set the goal of doing the first and seeing if the third happens. (That may be exactly the kind of thing you postpone till the book.)
In the humanities we tend to conflate the conclusion with the implications (because we refer to both of them as the “so what?”). The sciences are a little clearer about this, and I think their sense of the difference is helpful for people writing a dissertation. If you think of the “conclusion” as the specific claim you’re going to make about your data, then the implications section is the highly speculative part–what might this mean in terms of scholarly discourse, pedagogy, policy, or practice. Students can paralyze themselves by thinking that they need to know either their conclusion or their implications before they write; you’ll figure that out eventually, but not now. You should be able, in your prospectus exam, to blather about some of the conclusions you think you’ll be able to draw if you do end up drawing one of the conclusions you think you might draw.
What happens in the course of writing the prospectus is that you narrow your various terms (keep in mind they may still be a little vague, and that’s fine). It seems to me that students can usually get started best by thinking about texts–which might be defined by author, kind of author, theme, problem, genre, era, movement, or some combination. People usually end up writing about fewer texts than they thought they would, so don’t try to be too ambitious.
What really surprises students is how narrow “the” disciplinary conversation is that you will be entering. You don’t want to try to change how people in rhetoric think about something (well, maybe you do, but writing a diss is a small step toward that). You will instead be trying to change the conversation among people who have written about your texts (or kind of text, or problem). You might slightly expand that–try to talk to people who haven’t written about your texts, and you think should have. (So, for instance, if you are writing about an era, genre, author, or whatever that is usually dismissed.)
So, how do you start writing? Well, NOT the way that you probably wrote your seminar papers. You probably came up with a sense of structure and then wrote what you thought would be the first part and wrote till you got to what you thought would be the last part. Then you wrote your introduction. As I said above, it seems to work best for most students if they begin by writing whatever “part” seems clear or compelling or fun.
To say that it is clear is not to say that you know what you want to say, but that you might be certain that you want to write about a certain text–for many people, starting with close analysis is great. Some people find it helpful to write about the abstract and the specific around the same time; if that’s the case, then do it that way. The point is that you just need to start writing.