This recent re-reading I had of Lord Foul's Bane, the only thing that came to my mind when I read about the rape was "Ignorance".
Rape is a horrible act, really no words can define it or give it justice. It has been awhile since I read "the Gap" Series. I wasn't aware however the sexual violence was a recurring theme in many of SRD's books.
I've often thought about why he (SRD) made TC rape her. When I was young I felt an instant revulsion when I read the book for the first time cursing TC for his stupidity. But not now. I muse that perhaps the rape was essentially a plot device. It was a way to cement in the readers mind that the protagonist did indeed have "issues". It also ensured that the reader would not try and personify themselves too closely with TC. TC gets verbally abused many times in LFB. He is insulted in Soaring Woodhelven with distrust and handled rather roughly for example. If the reader felt too closely tied to TC they could conceivably take personal offense at many of these narrative junctions. At one point Quaan the Warmark threatens to break both of TC's arms if he continued speaking.
I think however the issue of rape cannot be understood, like many of life's tragedies unless you have somehow felt the pain involved. The same could be said of leprosy. It should be no surprise that the main character of the series is a leper because of of SRD's background.
Stephen R. Donaldson was born in Cleveland on May 13, 1947 to James R. Donaldson, a medical missionary, and Mary Ruth Reeder, a prosthetist. From the age of four to sixteen, he lived in India where his father worked with lepers.
(taken from:)
speccoll.library.kent.edu/literature/pr ... n/bio.html
However sexual rape and violence would not be so readily documented, in any context with regards to the author, SRD.
In order to understand the first thing about rape you must dismiss a common misconception.
Rape is not a
sexual act.
Rape is an act of
power and violence.
Power of the perpetrator over the victim. It's a well documented fact. With this forebearence in mind it's impossible to excuse Covenant for his actions by rationalizing that the actions took place as a result of a sudden recindence of impotency. The very implication of sexual function or ability has no meaning when the true definition of rape is taken into account.
You could argue that the rape was therefore commited because the nature of TC's existence was leprosy and that leprosy is essentially a curse of inability. Helplessness. A loss of control on many levels. Rape is a means of power and control. You could argue that this need for control was what was paramount and the driving force behind TC's psyche the instant he began to rape Lena. He needed an instant measure of control, any control when faced with the limitless possibilities and verdency of "the Land".
When I was younger I was sure that the series could have been written without the rape inserted. Now older I see the gloaming of Lena's family tree all stemming from that one sad act. Atiarian Trell-mate summoned Hile Troy as a result (and died), Trell Gravelingas invoked the Ritual of Desecration wrought from his personal despair as a result, High Lord Elena was born to Lena as a result and the list goes on and on.
Perhaps SRD wrote the rape in also to clarify the wretched state of Thomas Covenant's being. He knew perhaps the fact of reading on paper that TC was a Leper just would not carry any emotional depth to the new reader. People react strongly to situations or issues they can relate to in some form or shape or even to issues they have some idea about. How many forms of media can we see in any part of the world that we can turn to at the flick of a switch or press of a button that deals with Rape or sexual violence? How many can we say the same for leprosy? Very little of course. Want to get someone's attention at the beginning of a story? Leprosy would seemingly fade even if you perpetually put down on paper the physical and mental horrid conditions of that disease, but rape? Rape invokes very strong emotions as well as an instant mental picture.
Rape is personal anathema to me. If it enters any story line or visual medium / artform it
will get my attention.
Could SRD get away with not having the rape in the storyline now? We are all more or less attached to the story the way it is. I don't think I would want it changed regardless of the personal revulsion I feel for the act.
The more I think the more I could post so I'm going to stop my long giantish tales "I am a Giant of Seareach. Make no short songs for me." and end
here.

Covenant recognized that this was a fact. But he had not expected such an argument from the Giant.
"Foamfollower'" he muttered, climbing out of his bed, "you've been thinking again."
from: "Lord Foul's Bane"