The list could go on and on, and in each case the person committing the act of dishonesty told themselves they had a perfectly valid reason why the end result justified their lack of integrity.
That's very much the core of the problem - the human ability to rationalise.

I also really loved this:

Warren Buffet, Chairman and CEO of Berkshire Hathaway said it best:, “In looking for people to hire, look for three qualities: integrity, intelligence, and energy. And if they don’t have the first one, the other two will kill you.”
So true!