Additional Discusion, pp. 712-723
The Pyncher certainly does have a thing about S&M, doesn't he? It was all over Gravity's Rainbow, Katje Borgesius and all, completely absent from Mason & Dixon, and now here it is, back with a whipcrack.
What's up with that? On the M side it's all about the willing surrender of power over one's body to another, and the concordant acquisition of said power on the S half of the equation. And given that Pynchon concerns himself at rather great degree with power relationships -- political, physical, religious, economic -- I suppose it's not a great stretch to see rather obvious metaphorical uses for it.
No great insights from me on the question. Just thought I'd hang it up and see if anybody knouts it.