I was certainly associating intent with soul when I read the passage on "soul and body unified". And "moving the back vigorously" makes a whole bunch of sense given how much of this work is driven by unifying the body through the back. It's one of the first things Sensei introduced to us and I keep coming back to it in my own practice.
O-Sensei referring to people being unbalanced on contact... that came up in recent discussions, didn't it? I think it came from one of his interviews, maybe the one with Kisshomaru. Yeah, that's another reference I understand totally differently now than I would have earlier.
Graham--thanks much, I was nuts trying to figure out Dan's reference
WRT the spiritual aspects... I don't actually disagree with much of what Andy wrote, understood only on a spiritual level. But I see that level as a layer on the Aikido level, which is a layer on the aiki, which is a layer on the jutsu. Without the lower layers of an effective martial art the spiritual layer is but a "beautiful and ineffectual angel, beating in the void his luminous wings in vain."