*PS - One of the reasons that I am on Nishijima Roshi's "sh-t" list these days is that I told him over recent years that I thought he had taken his very good ideas of Zazen as "Balance of the Autonomic Nervous System" and of Zazen having a neuro-physiological basis, and had stretched his ideas rather too far into areas where there is no scientific backing, no data, or where scientific data is directly contradicting some of what he says. I said so with all tact and respect for his (then nearly) 90 year old person, but like some of our parents and grandfathers, he does not take any contradiction well these days. He has become a kind of "my way or the highway" fellow on this issue.
One has to be very cautious about speaking to one's seniors in Japan. That whole "hari-kiri" sword in the belly thing (I have avoided that so far).
So, for the past couple of years I just stopped mentioning the subject when with him, and let it slide. I even just took the easy road to agree with whatever he said and say "yes yes" (he is very near the point now where everything in Buddhism comes down to "balancing the Autonomic Nervous System") But, once he had me marked as disloyal to his theory a couple of years ago, he never trusted me quite the same way.
I want to be perfectly honest about the situation.
He is a wonderful teacher of Shikantaza, Dogen and Zazen ... but some of his "theories" about what those all mean are his own invention that have run a bit wild over time. I think.