It sounds like this is far more of a matter of pride to your father than it is genuine concern. If you can do just as well, if not better, in a different school then that should be what he considers, not the 'challenge' of it. I can't imagine you could tell him that without making the situation worse, however, so I'd recommend trying to explain why you feel you want to go to a different kind of school. Try to do it on an emotional level, I think. I find that works better with most people than cold logic does, as much as I hate to use it.
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Power corrupts. Knowledge is power. Study hard. Be evil.