Evil is the perversion of human perfection; it is the mind turned in on itself to hurt, harm, demean, and destroy other people, along with their possessions and their most valued symbols. If we take Good as the natural human condition, then Evil is its antithesis, and Heroism its opposing force. But that triad represents multiple facets of human nature. This terrorist attack on U.S. sovereignty represents a new level of creative evil in which human intellect serves the basest motives of violence and destruction.

It is imperative not to underestimate the power and catalytic force of this new enemy, and we have to change our perception of this attack as "senseless violence." Of course, this tragic destruction of lives and property does not make sense to us because it is incomprehensible that any individual or group would engage in such evil deeds. But calling it "senseless," "mindless," "insane," or the work of "madmen" is wrong for two reasons. It fails to adopt the perspective of the perpetrators, as an act with a clearly defined purpose that we must understand in order to challenge it most effectively. And such negative labeling also lulls us into thinking it is random, not comparable to anything we do understand, and making us disrespectful of the high level of reasoned intellect behind these deeds, however distorted or diabolical it may be.

Constructive efforts at preventing future similar acts of international violence best begin with attempts to understand not only the Who question, but the What question as well. Our national leaders will seek out those who orchestrated this destructive attack against our nation and eventually bring them to justice. But even if the identifiable terrorist leaders were to be eliminated, would that stop future terrorism? It is unlikely, unless we know what are the root causes of the hatred against America; unless the ideological, political, and social bases of the mentalities of the next generation of potential terrorists are more fully appreciated and efforts to change them are engaged.

Evil has always existed in many forms and will continue to flourish in different ways in different places. There are individuals we acknowledge as embodying evil, just as Lucifer and Satan do--Hitler, Stalin, Pol Pot, and other national tyrants. They are all dead, yet evil flourishes throughout the world with nameless conductors orchestrating ever new violence. It is well for us now to go beyond our tendency to focus on dispositional evil as a peculiar property or characteristic of despicable particular individuals. Instead, we might consider focusing on the determinants of evil in order to to identify the breeding grounds that can seduce even good people to become perpetrators of evil.

Even while acknowledging our individual and national need for retribution and punishment of the leaders of this terrorist attacks, we must realize that without altering the fundamental sources of anti-American and anti-democratic beliefs and values in other nations, new replacements will emerge for each tyrant leader we punish or kill.

Much psychological research reveals the ease with which ordinary people can be recruited to engage in harmful behaviors against their fellow human beings. In one classic study by Stanley Milgram, the majority of ordinary American citizens who participated in it blindly obeyed an authority figure and administered what they believed were painful, even lethal shocks to a stranger.

Albert Bandura showed that intelligent students were willing to be extremely aggressive toward other groups of students merely because they were characterized with the dehumanizing label of being just "like animals."

In another demonstration from my own laboratory, normal college students recruited to role-play prison guards became their roles in a matter of days, behaving with escalating violence and sadism toward their prisoners--other college students. We know that a cult leader, Jim Jones, reverend of Peoples Temple, was able to program his followers to commit suicide, or to kill one another on his command, and more than 900 American citizens did so in the jungles of Guyana.

Research by John Steiner (an Auschwitz survivor) indicates that most Nazi concentration camp guards were "ordinary men" before and following their years of perpetrating evil. Many more examples could be culled to illustrate reasons why we should not demonize these terrorists as an alien breed. Instead, we should focus on a better understanding of the mind control tactics and strategies that might make even good people engage in evil deeds at some time in their lives, and that might recruit new generations of impoverished young people into lives of terrorism.

We need also to acknowledge openly "the dark side of religion" in terms of how religiously based value systems can be perverted to justify and reward the most horrendous of human deeds. Unbridled evil has been carried out in the name of religion and condoned in the name of God over the centuries by most nations of the world, and still is.

The efforts of our military forces in tracking down and destroying the terrorist leaders has a collateral risk. It models revenge and retaliation at a national level which can become a stimulus for individual hostility toward innocent citizens in our own country whose ethnicity, religion, or appearance might be similar to those of the terrorists.

Research by Dane Archer shows that homicide rates increase dramatically following all wars, the same for victor or loser nations, presumably because individuals learn to use violent means of conflict resolution as had been sanctioned by their national leaders. We cannot allow that transfer of hostility to develop, because it fuels the cycle of violence started by the terrorists. Terrorists create terror; terror creates fear and anger; fear and anger create aggression, and aggression against citizens of different ethnicity or religion creates racism and, in turn, new forms of terrorism.

We must individually and collectively refuse to adopt the terrorists' devaluing of human life. If we do not, and we yield to the quiet rage of hatred that their vile deeds have generated in most of us, then our desire to destroy them at all costs will ally us more with the forces of evil than of good.

If we...yield to the quiet rage of hatred that their vile deeds have generated in most of us, then our desire to destroy them at all costs will ally us more with the forces of evil than of good.

We have seen the enemy--do not let it become us. We have also witnessed the tremendous outpouring of positive emotions, good will and heroic deeds of Americans in response to this tragedy. We are giving money and blood, selflessly donating our skills and energies, and even sacrificing our lives to help others.

This tragedy may in the long run help to nurture the best in us all, to rekindle civic engagement, to connect each more fully with family, friends and neighbors, to put community and nation before self interests. It may give us new reasons to be genuinely proud to be Americans who oppose evil with tolerance, compassion, justice, and love.