Dear Sir or Madam,
I have just finished your most recent book, and found it to be just the thing for me. The text was clear, the examples were useful, and it was required reading for my course, so there was that as well. There was just one problem.
Do you see what I did there? That’s what it feels like when you’re reading along, following the logic, and then, right after the final point is made, it just stops. The argument might be finished, but, from a reader’s perspective, it’s incredibly jarring just to have a last sentence, a last theorem, a last quote from the text you’re analyzing, and then nothing.
Which brings me to what my problem is. Your book had no conclusion. You went right up to the end of what you were saying.
I bet you were expecting me to say “and then you just stopped”. I did it again! There was no need to say that you just stopped after you finished saying whatever it was you were saying. It was clear from the context, so I didn’t bother to put it in, because apparently that’s how we all write these days.
Seriously, though, next time, please give me some kind of soft wrapping-up, at least a paragraph. Give me some way for me to pat myself on the back, congratulate myself for finishing the book, and properly decide how I felt about it. Let me pause and ponder the greater implications of what I’ve just read, rather than just thinking “Oh, I guess that’s where it finishes then”. Give me at least a closing sentence or two, please!
The purpose of a good conclusion is twofold. First, it tells me where what I’ve read should sit, relative to everything else I know. This is where one concluding line I actually saw once, “To a mathematics devotee, their mind is a solitaire game in search for the first step to climb the rainbow”, falls down.1 (Well, it falls down in a lot of ways, but this is the biggie.) If the author had just written “Great, now you know more about what my paper was about; go forth and do research,” I would have had the chance to step back and say “What else do I know about this? Where else have I seen information that has a bearing on it?” A conclusion is meant to be an invitation to take stock of what you have and work out where you go from here.
Second, a conclusion gives me some emotional closure. Call me old-fashioned, but I like my textbooks to be readable as well as erudite. If Pride and Prejudice ended just after Elizabeth rejected Mr. Darcy, that would be no good. You have to draw the story arc all the way to the end, and then make sure the reader knows the end has come. Even if the end has, indeed, arrived, I won’t be satisfied until you tell me. Without a conclusion, there’s always the nagging feeling that the guy who sold me the book ripped the last few pages out while he was bagging it. Rationally, I know I’ve got everything I’ll ever get from your book. Non-rationally (not irrationally), I don’t, and I never will, because you have no conclusion.
It doesn’t have to be long or fancy. I don’t need or want pages and pages extra. You’re quite right: much of the book should be devoted to important, concrete ideas. That’s why I bought it, after all. It’s perfectly possible to have a very satisfactory conclusion in even a paragraph.
Check this one out:
I mean no disrespect to any part of the text of your book as it stands. I just feel it would be strengthened by the addition of a little bit at the end, allowing me to both intellectually and subconsciously better understand how your book works as a unified whole within a larger field. This strengthens both your text and my understanding at the same time. I look forward to seeing your later works, most of which, I am sure, will now be perfectly concluded in exactly the correct style.
Michael Kielstra (email@example.com) eagerly awaits the new era of textbooks with satisfactory conclusions