That said, it would be irresponsible of me not to think through what barriers could arise that would potentially threaten the successful completion of her doctoral work. Of course there are all sorts of logistical and scientific questions to consider in designing her research, to make sure it will produce something that will be publishable and launch her on a successful career. But I have known enough doctoral students who stopped before getting a doctorate that I feel like I have a fair sense of what goes wrong, and the scientific difficulties (e.g., almost getting killed in Papua New Guinea) tend to cause delays, rather than make people stop altogether. I have not known any doctoral students who failed, in the sense that they produced dissertations that were simply indefensible. I have known many who didn't produce a dissertation or receive a PhD.
These nondissertators were in my experience no less bright, driven or well resourced than other doctoral students. Some of them suffered from health problems, scientific set-backs or family emergencies that exacerbated their situations. But the characteristic that unites them is that they were poorly matched with their Doctorvaters or Doctormutters. Sometimes it was a simple personality conflict, but more often the mismatch was in terms of the advising style and the need for advice. Students who need guidance and aid often end up with ultra-busy hands-off advisers. Students who need to be left alone to do what they already know how to do sometimes end up with micromanagers. I spent a fair bit of time as a doctoral student thrashing around, not getting as much advise as I needed, not even knowing what the rules of the university were. A good friend in another lab wasted a lot of time fighting with her adviser whose overzealous attempts to advise were often an impediment. Both of us at times considered dropping out, transferring to other labs, or committing felonies, but a combination of luck, pigheadedness and good burritos got us through. We had several peers who took other paths in response to adviser mismatch. It is a very rare student who will go to her adviser and say, "I want you to alter your approach to advising," and not all advisers would respond positively. I hope that my student will say this to me if necessary, and knowing her, I think she will. If she doesn't, I'll ask.
In the academic world, leaving the academic world is generally thought of, and often spoken of, as failing. If you are in a doctoral program and leave without your doctoral degree you fail. If you get your doctorate and then make a career in academia, you succeed. What I have done is clearly success, so to do otherwise is clearly failure. This is of course a definition born of bias and self-congratulation. My job as a Doctorfater is to simultaneously help my student to succeed in the traditional sense and to make it clear that other paths are not necessarily failures. Producing a garbage dissertation is failure. Finding an alternate route to a happy productive life is not. I hope that making this clear will help my student succeed, in the traditional sense.
*Vater in German is pronounced like 'Fah-tar' in English and means father. It has only just now occurred to me that Darth Vader's name was rather a large hint.