There are legal issues involved in that though. You need to have a real good reason for turning someone away. I am always trying to make sure I am not training the wolf to kill the sheep. I want to train the sheep to survive the wolf.

That was my point to having a good reason. You have to make sure that it isn't able to be taken as discrimination.

Julius Cesar, wrote in the "De bello Galica" : Se vis pacem para bellum ( If wants the peace be prepare to the war).

That latin expression is printed onto the back of one of my insructors T-shirts that he got at an instructors meeting in the Poland (for the IKMF).

i think it summarises the mentallity pretty well, even if a specific philosophy isnt outlined in great detail. The idea that shouldnt be starting fights, but when the time comes that you have no choice but to fight, you come out in the best condition possible. Simple as that. :-)
my 2 cents :P

Either take no action against someone, or if you take action, make it an unstoppable action.