|We won't forget.|
What really causes people to do these things is an unshakable conviction in their beliefs, including the belief that violence is the best way to accomplish their goals. If someone is absolutely convinced that the most effective way to protest a perceived problem with the government is to bomb innocent people, they may end up like Timothy McVeigh. If someone truly believes that God has told them to become a martyr and kill themselves along with the infidels, they may end up like those 19 hijackers. Once a violent belief has taken hold of a true believer, nothing will convince them otherwise. The mind of a true believer does not respond to logic or reason. Quite the contrary, in fact: such people will not only reject them, but also be proud of having seen through the evil deception of their enemies.
The root of the problem does not lie with a specific religion, or with religion in general, or even with ideological extremism. The very heart of what causes people to kill innocents is a rejection of the tools that have been proven to reliably find truth (like logic, science and skepticism) in favor of others (like dogma, faith and special revelation) that are superficially and subjectively convincing but hold no weight upon careful inspection. That doesn't mean that every religious or credulous person will fly a plane into a building. Far from it. But using the wrong tools for finding truth creates many more possibilities to arrive at the wrong conclusions. Wrong conclusions lead to false beliefs, and false beliefs can have very real and even catastrophic consequences.
So, this September 11th, I remember the victims with great sorrow, and the perpetrators with disgust. But I also remember the warped and biased methods they used to arrive at their conclusions. These, in the end, are what we're really fighting against.