I have spent some time researching and thinking about some koryu and their approach to combat. This is a topic of endless fascination for me as I find myself holding on to old, childish thoughts of "The Way Things Should Be", according to some primitive and deluded model.
Let's start with my delusions of martial arts from as early as I can remember.
Cartoons like G.I. Joe and shows like Kung Fu: The Legend Continues both were a formative part of my childhood, in some way or another. Not that they were necessarily my favourite shows, but I think they formed the basis for what I thought the martial arts were and what they should be. Most of all, how to learn them and how they were developed (somehow development got tied into how they were used). What is the first thing that the "Good Guys" do when confronted with an enemy? Drop their weapon to give their opponent a fighting chance! Clearly using weapons was a bully's resort of choice - the good guys didn't need weapons.
Enter martial arts movies - Bruce Lee, Chuck Norris, Jackie Chan, Steven Seagal. When the going gets tough, the tough use their bare hands.
So, in my mind, until the last year or so, I never really understood the formulation, usefullness and purpose behind the weapon arts. They just seemed like something cool and superfluous.
But back to my original point - koryu. Kenjutsu, jujutsu, iaijutsu - the list goes on. What are the relations between them and how do lessons from one apply to the other. I recently saw an interesting video (which I might dig up, if I can) in which a Sensei was showing the purpose behind some sword work through the use of empty-hands. The subtle but critical arts of distancing, timing, entering and capturing balance, all within the "simple" movements of a downward cut. Another lessons learned.
The one thing I love about the martial arts is that you can learn sometimes as much from reflection while not physically training as from messing about with a comrade.