The key thing I learned was that you're done when you decide you're done. From what I've seen, if you sit down and write a dissertation, it's a rare committee

The key thing I learned was that you're done when you decide you're done. From what I've seen, if you sit down and write a dissertation, it's a rare committee that will stand in your way. This even includes a friend whose advisor refused to read his dissertation -- the rest of his committee approved it and the advisor was pressured into compliance. (In this case the advisor wasn't adversarial, just always "too busy" and didn't want to lose my friend's almost-free labor.) In my own experience, I had a year that was almost completely wasted. I almost gave up, but instead I decided to stop trying to do work that other people wanted. I wrote the two chapters I wanted to write, because it was the only way they were going to get written, and in the end the committee was fine with them.