"I believe that what I do becomes part of me," she said. "When I'm brave and strong, and care for children and the sick and the poor, I become a better person. And when I'm cruel, or cowardly, or tell lies, or get drunk, I turn into someone less worthy, and I can't respect myself."
Caris from World Without End by Ken Follett
It's certainly not a new idea but one worth repeating.