One example is the Western intellectuals who viewed themselves as humanists who nevertheless supported Stalin, believing that his atrocities were necessary steps for achieving a better future for humanity.
But if we do not accept this principle, what is the alternative? Reality is complex and it is an illusion to imagine that we can do what must be done without a price. In Israel we know that the means necessary to fight terrorists invariably will be at the cost of inflicting casualties on innocent civilians as well.
Parshat Toldot presents us with this moral dilemma. Yaakov deceives his ageing blind father in order to take the blessings designated for Esau. Did he do what is necessary for the future of the Jewish people or was his behavior unacceptable, deceiving his own father and causing him great anguish?
When there are only two possibilities and neither are acceptable, choose the third. The Zohar teaches the third path.