...and to add a litle bit of perspective to the debate, in the last year I have flown with 3 PhD's as my First Officer. One humanities-based (I forget which discipline,) one Applied Mathematics and the other Chemistry. The last chap had been a Rocket Scientist, building engines for satelites and one of the Mars lander projects.
None were "too bookish," all were excellent pilots and good company, with a story to tell downroute.
So go for it if you want to. It's an uphill struggle, but so's getting a Phd. I'd agree with the advice to finish it first, however...
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