Re: how do we define martial?
Graham I believe you to be 180 degrees off. Martial arts were born out of the need to fight. All cultures and civilizations have developed martial practices in order to protect, defend, and to further their societal goals. Some are more codified than others. Thus, all martial arts by nature and heritage are rooted in the basic need to fight.
As far as the spiritual aspects etc. Well any sustainable society that has produced warriors understands the need to for balance and moderation. Much of what is done in martial arts is good for you mentally as well as physically. The spiritual linkage...well, I think that is quite a different subject and alot of imprinting is done along with way to link the physical and spiritual dimensions. However, the need for martial arts is in no way born out of the need for spiritual development but simply to fight. I think this is abundantly clear.
Of course, people can realize spiritual benefits as they attempt to reconcile the violence they feel through the practice of martial arts. I can tell you it has been a good outlet for me. but so is racketball, and parkour as well. Pretty much anything that engages the mind and body is good for us.
As far as things such as shaolin done in temples. I am not a historian, but believe that the monks practiced what they practiced to defend themselves. I am sure they realized early on that being in good shape benefited their spiritually as well.
Modern Japanese history, IMO, took the opportunity to revise and re-market their goods and practices as "spritiual practices" around WWII for what I think are fairly obvious reasons. There are scholars here on Aikiweb that can discuss this better than I.
the fact remains, at the base level, that anything that is called a martial art should and is grounded in a system of combat.
and yes, the art of loading and firing cannons is a martial art.