I just want to get this idea in print, maybe get some feedback on it.
I have been saying for less than a year that perhaps translating Neijia as "internal school" is limiting. Perhaps it should be translated "inward school." That would make Waijia the "outward school." Why? because I think once we truly discard the idea of cultivating power, or storing up power, the idea of using outward moving force seems unnecessary. Outward moving force, by definition, breaks whole body unity. Basically I'm talking about the habit of pushing. By pushing I mean specifically having a hand on the opponent and a foot on the ground and using force to increase the distance between the foot and the hand.
Inward moving force, by definition increases whole body unity. Maintaining whole body unity while fighting requires us to use all of our weight (gravity) with momentum to have an effect. When every movement is using our entire weight for momentum, a small contact point (surface area) or a small amount of time (in contact), can have a very large effect. Large effects from small events tend to create big unconscious reactions in opponents. We call this effect lightness skills, as opposed to the more common, heaviness skills.
Anyway, I was just explaining to a puppet maker in Israel that although all muscles pull inward towards the center, most people do not perceive their bodies that way. And because of that I can create all sorts of illusions of power. She got this right away, saying something like, "Yes, it is totally obvious that all muscles move inward, just look at how we construct puppets." She was making a very realistic type of puppet with articulated joints, a nylon string embedded in the body of the puppet was used to mimic the shortening of a muscle. You can't push a string, you can only pull them, or delay releasing them when you have pulled the other side of the joint.