Nathan Yau has written an excellent post on starting and finishing a Ph.D.. This really captures much of the essence of what it means to go through the experience, and what you’ll need to do it. In short, you’ll need: passion and grit. Lots of grit. Smarts are important, to be sure; but, there are plenty of smart people in this world. It’s the mettle that gets the job done. If you’re thinking about pursuing a doctorate, in any field, this is a must read. If you’re in the middle of, or have completed, a doctorate, it’s still worth reading, if not for the sake of reflection.