I'm considering a total shift in my career from IT to non-profit management. I've informed my boss that I'm want to go graduate school and to do this I'd like to go from full-time to part-time in the office. He's been asking why I want to go back to school. I haven't told him because I don't want him to think I'm not committed to the job/career I have now. He's also not the most tactful boss and I fear being riducled for going into "soft" area of business instead of the macho industry I currently work in.
How do I bring up my desire to get degree in non-profit management and become an executive of a non-profit to my boss without him being threatened?