The following warning appears on the front page of BASEjumper.com:



QUICK HEURISTIC

Imagine that there is no degree given and no chance at all of getting a job in the field afterwards. Would you still go? If the answer is no, then you shouldn't bother.

This is true of most American PhD programs in most fields with no clear industry demand, including theoretical mathematics and physics. The details I fill in here, however, are specific to philosophy -- the field I am most familiar with.

THE 411

This is a bad idea for social, economic, and health-related reasons. The stats are pretty awful, you risk having no job, and you will not be putting down roots and will have to uproot multiple times. So, you are setting yourself up to be poor, have no close friends nearby in later years after grad school, and I am not sure how you are planning to retire either since, even if you successfully get a PhD and get a tenure-track (at the best programs, flip a coin to see your odds), you'll miss out on about a decade of retirements benefits and potential savings too. Needless to say, if you are a philosophy major and all you see ahead is having to choose between law school and phil MA/PhD, you should see a good career counselor (if you see a crappy one, really, try to find a good one -- it's one of the most important decisions you'll ever make) or stay in school another two years and get a major in something with market demand, go teach k-12 or join the Air Force, or go to a community college and get a degree in something healthcare related, which will be much cheaper and will have a much higher payoff in the long-run (and don't worry, your phil skills won't go to waste). Also, job and life satisfaction is, on average, pretty low even after tenure in part for the reasons that I said above, but other things bother people too. This is why Brian Leiter says on his website that should do this only if you can't do anything else and better be really sure this is the kind of life you want (or something like that). If you really still need to think about it, here is some more information and some concepts to help you think through your decision:

Analytic Approach
Continental Approach