The evil of the world is made possible by nothing but the sanction you give it. - Atlas Shrugged

Evil requires the sanction of the victim.

...When you have established that one alternative is good and the other is evil, there is no justification for the choice of a mixture. There is no justification ever for choosing any part of what you know to be evil.

Learn to distinguish the difference between errors of knowledge and breaches of morality. An error of knowledge is not a moral flaw, provided you are willing to correct it; only a mystic would judge human beings by the standard of an impossible, automatic omniscience. But a breach of morality is the conscious choice of an action you know to be evil, or a willful evasion of knowledge, a suspension of sight and of thought. That which you do not know, is not a moral charge against you; but that which you refuse to know, is an account of infamy growing in your soul. Make every allowance for errors of knowledge; do not forgive or accept any break of morality.

In the many months of his absence, she never wondered whether he was true to her or not; she knew he was. She knew, even though she was too young to know the reason, that indiscriminate desire and unselective indulgence were possible only to those who regarded sex and themselves as evil.

The man who refuses to judge, who neither agrees nor disagrees, who declares that there are no absolutes and believes that he escapes responsibility, is the man responsible for all the blood that is now spilled in the world. Reality is an absolute, existence is an absolute, a speck of dust is an absolute and so is a human life. Whether you live or die is an absolute. Whether you have a piece of bread or not, is an absolute. Whether you eat your bread or see it vanish into a looter's stomach, is an absolute.

There are two sides to every issue: one side is right and the other is wrong, but the middle is always evil. The man who is wrong still retains some respect for truth, if only by accepting the responsibility of choice. But the man in the middle is the knave who blanks out the truth in order to pretend that no choice or values exist, who is willing to sit out the course of any battle, willing to cash in on the blood of the innocent or to crawl on his belly to the guilty, who dispenses justice by condemning both the robber and the robbed to jail, who solves conflicts by ordering the thinker and the fool to meet each other halfway. In any compromise between food and poison, it is only death that can win. In any compromise between good and evil, it is only evil that can profit. In that transfusion of blood which drains the good to feed the evil, the compromise is the transmitting rubber tube.