For everything there is a season and a time for every matter under heaven. A time to love and a time to hate; a time for war and a time for peace (Eccl. 3).

One of the most frequent themes of my writings is how we - a generation with a fifty percent divorce rate and a professional singles scene - have forgotten how to love. Today I will surprise you by complaining about how we have forgotten how to hate.

The proper response to the cowardly brutes who perpetrated the horrific attacks against America is to hate them with every fiber of our being and purge ourselves of any morsel of sympathy which might seek to understand their motives.

Forgetting how to hate can be just as damaging as forgetting how to love. I realize that, immersed as we are in a Christian culture that exhorts us to "turn the other cheek," this can sound quite absurd. Little do we remember, it seems, the aphorism that those who are kind to the cruel end up being cruel to the kind.

Indeed, exhortations to hate all manner of evil abound in the Bible and God Himself hates every form of immorality because of its harm to mankind. Thus the book of Proverbs declares, "The fear of the Lord is to hate evil." Likewise, King David declares regarding the cruel: "I have hated them with a deep loathing. They are as enemies to me." Hatred is a valid emotion - an appropriate response - when directed at the truly evil: those who have gone beyond the pale of human decency by committing acts which unweave the basic fabric of civilized living. Contrary to Christianity, which advocates turning the other cheek to belligerence and loving the wicked, Judaism obligates us to despise and resist the wicked at all costs.

About two years ago, I was on the BBC discussing the tragic bombing of a gay pub that left three dead. I referred to the bomber as an abomination, to which Pastor Tony Campalo, President Clinton's spiritual advisor, replied that we had to love the bomber in the spirit of compassion and forgiveness. Similarly, in my years in Britain I was used to hearing victims of IRA terrorist attacks, after having lost fathers or brothers or sons, immediately announce on air their forgiveness and love for the murderers, in the spirit of Christian love. I disagree vehemently. The individual who, motivated by irrational hatred, chooses to murder innocent victims is irretrievably wicked. He or she has cast off the image of G-d that entitles them to love and has forfeited their place in the human community.

Amid my deep and abiding respect for the Christian faith, I state unequivocally that to love the terrorist who flies a civilian plane into a civilian building or a white supremacist who drags a black man three miles while tied to the back of a car is not just insane, it is deeply sinful. To love evil is itself evil and constitutes a passive form of complicity.

Contrary to those religious figures who deny Solomon's proverb and preach that religion is about unconditional love and forgiveness for all, I believe there is a point of no return for the mass-murderers of this world. The Talmud certainly teaches that the true object of proper hatred is the sin, not the sinner, whose life must be respected and whose repentance effected. The Talmud also teaches that it is forbidden to rejoice at the downfall of even those sinners whom it is proper to hate: "Rejoice not when thine enemy falleth." However, this attitude does not apply to impenitent and hardened monsters who pay no heed to correction. For us to extend forgiveness and compassion to them in the name of religion is not just insidious, it is an act of mocking G-d, who has mercy for all, yet demands justice for the innocent.

I have an a typical Christian artist friend who showed me a picture he painted of Jesus embracing Hitler. I felt the picture to be obscene, "How can you have Jesus holding Hitler?" I objected.

"That's the whole point. That's how far Jesus' love extends."

"But that's not love," I corrected him, "it's disgust. It's like saying that Jesus loves cancerous cells. If you love Hitler, than you are showing contempt for the good and decent people whom he turned into ash and lampshades. The only response to Hitler is utter contempt and violent hatred. The only way to react to incorrigible evil is to wage an incessant war against it until it is utterly eradicated from the earth."

I maintain that any culture that does not hate Hitler and his ilk is a non-compassionate society. Indeed, to show kindness to the murderer is to violate the victim yet again. Thus, in the interest of justice, the appropriate response to the evil person is to hate him with every fiber of our being and to hope they find no rest, neither in this world nor in the next.

The pacifist will respond that fighting hatred with hatred accomplishes nothing, that, as in the old Bob Dylan song, "if we take an eye for an eye we all just end up blind." This is poppycock because the purpose of our hatred is not revenge, but preservation of justice. To this end I wholeheartedly embrace the example of Simon Wiesenthal, one of the most inspirational men of the twentieth century, who has devoted his life to the pursuit of justice by not allowing Nazi murderers go to their graves in peace. We do not hunt Nazis in order to take revenge. We Jews have better things to do with our time than chase a bunch of pathetic, murderous thugs. Besides, our Torah prevents us from taking retribution. Rather, we track them down because G-d at Sinai entrusted us with the promotion of justice, turning the jungle into a civilized society. We seek them out on behalf of all humanity so that all of the world may know that for genocide there is no apology. In the words of Aristotle, "All virtue is summed up in dealing justly."

Justice is not a cultural construct. Neither is it a human invention imposed upon the members of society in order that they treat each other with decency and respect. Justice was not created for some utilitarian end. Rather, justice is intrinsic to human nature. We do not teach our children to refrain from stealing because they might get caught. Rather, we teach them that theft is intrinsically wrong, even if they could get away with it.

In the Hebrew language there are three words for forgiveness: selicha, mechila and kapparah. The essence of the forgiveness is that an individual is so valuable that we allow them the opportunity to start afresh after error. But since repentance is based on recognizing the infinite value of human life, its premise cannot be simultaneously undermined by offering it to those who have irretrievably debased human life. For a murderer to cry in public and achieve instant absolution is an affront to everything forgiveness stands for and that's why we should feel no guilt for our feelings of revulsion and hatred toward these terrorists.

The bottom line is that there are some offenses for which there is no forgiveness, some borders whose transgression society cannot tolerate under any circumstances, and mass murder is foremost among them.

Only if we hate the truly evil passionately will we summon the determination to fight them fervently. Odd and uncomfortable as it may seem, hatred has its place. Although they referred to a different era in history, the words of Martin Luther King, Jr., still ring true today: "We will have to repent in this generation not merely for the vitriolic words and actions of the bad people, but for the appalling silence of the good people."

Let us make sure, therefore, that we never make the mistake of forgiving those whose sin is so inextricably woven with their rotten character that the two can never be separate. Let us love the righteous and fight the wicked. ___

Rabbi Boteach, formerly the Chabad Rabbi at Oxford University, is a well-known author and lecturer on Judaism. http://www.arutzsheva.org/