Peter - If reach an impasse, I am content to have reached an impasse. I want to be sure such an impasse is reached, rather than us talking at cross-purposes, caught by nuance rather than true disagreement:
1. My absolute is that the infliction of physical pain, the disruption of attachment at an early age, the witnessing and experiencing of horrific incidents affect character. Thus, they are a significant component in the development of Takeda's character. It is my belief that, combined with the innate character that he was born to have (nature AND nurture), that this is a key to his wandering - his serial relationships of close disciple, then either distance or rejection, AND he relationships with his own family. I am attempting to be an advocate for Takeda, who has been described as evil, as psychopathic, whereas I see the central endeavor of his life as a path towards morality and attempts to connect with others and bequeath something to them.
Hence the sub-chapter heading "Sympathy for the Devil"
2. If the word "torture" is not on the mark to you, I would still assert that having moxa burned on one's fingernails so that it damaged the nail beds permanently, something that Takeda obsessed about enough that his son mentioned it prominently in his bio of his father, and Sokaku himself highlighted it in the only interview we have, makes it of symbolic import in Takeda's own sense of himself. So one can drop the word, torture, if one likes, (I don't, but that's neither here nor there), but it would be wrong to deny it's significance to Sokaku.
3. I do not think Sokichi needs an advocate. I actually advocate for him. I wrote:
One wonders what kind of father Demon Sokichi would have been in the best of circumstances. But he, too, had been to war and seen his Aizu ravaged, and he had a child, innately defiant and proud, and now - horrified. All too often, I have seen frustrated, desperate parents use outlandish methods to discipline their unruly child. The child, who, given his make-up and circumstances, is acting in a way that is completely natural to him, becomes more profoudly psychologically damaged by the parent than he was from the original trauma.
I empathize with Sokichi's dilemma as a parent - that despite his best attempts, despite is power and demands, Sokaku did whatever he wanted - defiantly - refusing even to learn to read. An defiant angry child is not tamed by harsh methods, that's for sure. And to be clear for the readers who have not read the book, "Demon" was the nickname Sokichi's own men gave him - not an appellation I'm applying.
My grounds for empathy
Back when I was 19, I roomed with a guy who had a labrador puppy - a sweet dog, who was bereft at being separated from his mom. My roommate worked in the day, and I'd be alone with this defecating, whimpering, crying, shrieking thing that kept climbing over me for comfort. I'd never taken care of a dog, I had no idea what to do to either train it or comfort it - and I used to throw it bodily into the garage. It would whimper and cry and try to get close to me. I shoved it away with my foot, and just stopped myself from kicking it. I hated it - and hated me for hating it. Luckily for me and the dog, I told my roommate that I was going to be gone during the day - every day - so he had to find somewhere else for the dog. "Helpless" caregivers are more common as abusers, in my experience than evil men. I describe Sokichi as the latter. This experience, by the way, scalded me enough that when I had children of my own, one in particular, very very strong willed, and I feeling helpless at times to guide or teach him, I had a warning - guilt - which kept me from trying to break my sons' wills to mine.
3. As for culture, one of the books that is a "Bible" to me is "Sick Societies," a book by a renegade anthropologist who takes the position that cultures can be pathological as well as individuals - and his definition is a cultural rule that damages it's members is pathological. (Note: he's not saying "them vs. us" - he cites quite a few pathologies in our own.). I agree that people experience things differently in whatever culture and time they are in - but often, cultural relativism is a product of distance. Foot binding in China, for example - was given a sophisticated context, including sexual fetishism, a particular attitude towards women, etc. We can explain it away, and explain it deeply - it was still mutilation at core, and inflicted terrible pain.
As I read this chapter, I considered that Sokichi also needed a spokesman (or defense lawyer) and I am not convinced that the traumas of the Boshin War were what led him to treat Sokaku in the way you describe.
All I state is that the Boshin war was a context for both Sokichi and Sokaku. You are reading in too concrete terms to interpret what I say as "this is the key" to all that Sokaku became. Merely, this is the context which, very likely, explains how Sokaku grew to be the wandering comet of a man he became. In the best of times, he would have been a proud, prickly, aggressive guy.
Nor do I think that your account of Sokaku's supposed traumas offers a more convincing explanation of the sources of Ueshiba's power than an account that places less emphasis on Sokichi's transgressions.
As for your last statement, at no point is that my assertion. The source of Ueshiba's power is, I believe martial information transmitted from Inagami Shinmyo-ryu through Kanenori through Sokichi to Sokaku, who took what he was given and made it bloom. That's a theory that only research might prove. To start with, it is a supposition based on a single statement attributed to Kanenori and some evidence of such training within the rubric of Chujo-ryu derived arts that led me to suggest Shinmyo-ryu as the source. It appears that Inagami may be Kanenori's own off-shoot of Shinmyo-ryu - HE may had changed Shinmyo-ryu himself! Unless some documents of Shinmyo-ryu surface which establish my theory, that's all it is. It's simply a lot more plausible than the standard line.
The source of Sokaku's character - a parallel concern of equal if not more importance to me - is nature and nurture. I am NOT - in any way - attributing Takeda's skill to how his father treated him, to the Boshin war, etc., except, possibly that his early experiences may have given him the drive to excel. These two things run in parallel to me. The chapter was not an attempt to tease out internal training skills on the part of Takeda as a product of bad experiences.
I tried to do three things: First, if possible, to trace a line towards the actual roots of Daito-ryu, the martial art. Second, to sketch out what I believe is a truer picture of Takeda's character, rather than the cartoon we usually have, where, as I stated above, "I see the central endeavor of his life as a path towards morality and attempts to connect with others and bequeath something to them." Three, some hint on how Takeda learned internal skills - this, the most minor of the three to me (having the least data to work with) is simply that his dad taught him, not Hoshina - and I would bet that were Sokaku the easiest kid in the world, had he the talent and the drive, his dad would have taught him too.