Joan Didion's classic essay "On Self-Respect".
Makes the point, among others, that what is critical is not that you avoid this or that misdeed -- she is clear about saying that people with self-respect still screw up, or screw around -- but how you deal with it, and with yourself.
Nothing else matters half as much.
The consequence of this is that ethics isn't really about doing good deeds or avoiding bad ones. It's not something you can do with a checklist. It's about who you are, at the deepest level.
You can find it here: http://www.vogue.com/3241115/joan-didion-self-respect-essay-1961/
