I think Ill second this.
Some arts has some philosophy teachings grafted onto it from the regional religions, but are they really underlying for the art itself??
What are those underlying philosophical concepts??
Martial arts based around group classes are not like individual fighter coaching, where anything goes. "It is like riding a bus. Everyone is going the same way and you aren't the one driving."
So the philosophy is the rout the driver is taking, and all the drivers get their training through the same channel.
When I go to wrestling class, it is clear that the people teaching think the way to go is to be aggressive and strong, and that you can't be aggressive or strong enough.
When I go to my kick boxing teacher, he thinks being aggressive before you hurt someone is a sucker's game and that the way to go is to get the other person to be aggressive so you can tell what they are going to do, and then to bend around that and defend yourself, always countering, because that is the superior way to conduct yourself.
When I go to Kenpo class, there is a feeling that the only people you will fight will be untrained, so the instruction is hyper aggressive. People walk around like they bruise the air. They like to break bricks and boards, perform high impact kata, and self defense techniques. It is mostly hitting, and the defense is still hitting.
Most martial arts instructors excel at arts that click with their personality, or they become true believers, and extend the fighting strategy of their art into their personal lives, as a general way of acting.
Wrestlers are standup, forthright, strong aggressive manly dudes. Kick boxers I trained with are passive aggressive, analytic, haughty, and mean spirited. Kenpo people are arrogant, tough, and self righteous. Here I'm talking about the leaders of the groups and people that have been there for awhile.
If you ask someone what the philosophy of the art is, they will give you some platitudes about standing up for the weak or not being a pussy. If you stick with a group for a while though, there is always a current that encourages people in the group to live and act a certain way, and that current is reflected in the training method. They don't have to know this for it to be true.