Principle

Yes, I harp on it, but there's a reason. Here's an example via Travis:

Dear Mrs. Bush,

I am writing to let you know why I am not able to accept your kind invitation to give a presentation at the National Book Festival on September 24, or to attend your dinner at the Library of Congress or the breakfast at the White House.

[. . .]

But I could not face the idea of breaking bread with you. I knew that if I sat down to eat with you, it would feel to me as if I were condoning what I see to be the wild, highhanded actions of the Bush Administration.

What kept coming to the fore of my mind was that I would be taking food from the hand of the First Lady who represents the Administration that unleashed this war and that wills its continuation, even to the extent of permitting "extraordinary rendition": flying people to other countries where they will be tortured for us.

[. . .]

When you give up your ethics and principles, it's almost impossible to reacquire them.