Yeah, but you forgot the dynamic part of the sphere's movement, sometimes describe as two-way action, and three-way motions. The simplicity of the circle is surely an easy picture to grasp, but the many actions that occur inside the circle as it is moving is what makes it dynamic.
So too, we push, raise up the bokken, and many times cause two way action while the third motion is taking place when we move in one of the eight directions ... don't be fooled into thinking that it is just your motions that cause the results, because there are three or more actions of your attacker/ partner that you match to achieve the harmony of action/ motion for Aikido.
Don't let any of this confuse you, it is just my observation after coming to Aikido from Kempo Karate/ Wally Jay Small circle Jujitsu. Professor Jay's proven techniques have slowly but surely proven out and seem to be creeping into Aikido schools in the last couple of years. I have no doubt that someone, somewhere, someplace would have brought back the small circle principles that work so well, so don't so browbeating me about Professor Jay. Have any of you studies the professors small circle jujitsu?
Which reminds me, how many of you have used Aikido in BJJ classes only to be told,"... not to do that" or " ... we don't do that here." Gee, all the stuff that neutralized grappling was not allowed, go figure. Maybe because everything in grappling is adrenalin driven macho he-men forcing their way out of a hold or tapping out when unconsciousness or injury is immenent.
Come to think of it .... there are three places you could be in relation to the dynamic sphere. You could be inside, outside, or on the surface of the sphere, which some people might not accept as half in and half out, but then again ... the solid model of mother earth might give more than three places one could be in relation to the sphere, eh?
Never mind, too weird. Just take whatever works for you, and build on it.
Enuf said.
