Last Friday I was in Pittsburgh, PA, to deliver a talk on science and pseudoscience for the local annual “Sagan Fest,” named after the astronomer and science popularizer Carl Sagan, one of my intellectual role models. It was an engaging, constructive moment of critical reflection, and even fun over drinks and dinners with the students and faculty of Carnegie Mellon University that organized the event.

Then, when I got back to my hotel room, I was greeted by a text message from my companion, which simply said “Did you see what happened in Paris?” I hadn’t, but I knew instantly that whatever it was, it wasn’t good news. I also knew that it had to do with a terrorist attack.

I loaded the front page of the New York Times on my browser, and I was greeted to the images and descriptions of events that we are all familiar with. At current count, the ISIS orchestrated attack has resulted in 129 dead and 352 hospitalized, many in critical condition. I’m sure the death toll will eventually be higher.

I have not read much in the way of commentaries and analyses as of yet. First, because I don’t believe they will tell me much that is going to be new or insightful about the event or their context — these things are becoming part of “normal” life, unfortunately. Second, because I wanted to think things over on my own, and see if my recently adopted Stoic perspective would be at all useful under this sort of circumstances.

Perhaps the most obvious difficulty for a Stoic when faced with horrors such as the Paris attacks (and let’s not forget the ones in Beirut, or Kenya), is the idea that people don’t do evil on purpose, but out of ignorance. Here is how Marcus famously puts it:

“Begin the morning by saying to yourself, I shall meet with the busybody, the ungrateful, arrogant, deceitful, envious, unsocial. All these things happen to them by reason of their ignorance of what is good and evil. … I can neither be injured by any of them, for no one can fix on me what is ugly, nor can I be angry with my kinsman, nor hate him.” (Meditations, II.1)

Right, go tell the friends and relatives of the victims that they should not hate the perpetrators, or not be angry at what happened.

Of course, Stoicism is not alone in this. Both Christianity and Buddhism have similar sentiments, and so do a number of other religious and philosophical traditions. But maybe they are just all mistaken.

Then again, perhaps it is precisely the occurrence of events like the Paris attacks that can be used to seriously probe our most fundamental assumptions and test our most cherished beliefs. So let’s consider for a moment what it would mean, from a Stoic perspective, to try not to get angry or hateful, and to really entertain the thought that ISIS fighters do what they do out of ignorance. What would that mean in terms of our response to acts of terror and their perpetrators?

Shock, anger and even hate are natural human responses to tragedies like this one. We cannot avoid them, they originate from the depths of human psychology and nature. But shock is paralyzing, and anger and hate are negative, destructive emotions. If we simply yield to them, as Seneca remarked, they will lead us to act under the spell of a temporary insanity. What a Stoic should do, then, is to turn the initial destructive emotion into a constructive one, which will take the deployment of at the least three of the four cardinal virtues.

To begin with, we need to summon courage, specifically the moral courage to stand up and be counted among those who oppose all that ISIS stands for. I don’t mean just adding yet another hashtag to your social media stream, or temporarily changing your Facebook profile photo. I mean something a bit more substantial, like standing with the majority of Muslim in your country who themselves reject ISIS, or opposing politicians who are already using the attacks for cynical purposes, like blocking asylum for refugees of the conflicts in Syria and surrounding areas — apparently oblivious to the fact that those refugees are abandoning their homes and countries precisely because they don’t want to live under ISIS or other oppressive regimes.

Next, we should channel our anger and outrage into a renewed exercise of the virtue of justice, demanding of our elected representatives that they truly do whatever is in their power to help react in the proper way to the threat of Islamist terrorism, to keep in mind that the goal is to bring about a safe and flourishing human community, not to use external threats for political gain, or to push agendas that result in the demonization of minorities and immigrants and in the restriction at home of those very liberties that we are allegedly trying to protect from the assault of ISIS.

Which brings me to the most difficult of all virtues to practice and deploy: wisdom, particularly the practical wisdom of knowing what the best thing to do is under difficult and complex circumstances. This requires critical reflection as well as what I would call principled pragmatism — seeking what works in practice, even if not ideal, while at the same time keeping in mind the fundamental principles we cherish and wish to defend. What the exercise of wisdom certainly does not mean is what we we will surely see plenty of in the next days and weeks: demagoguery, fear mongering, and simplistic slogans that fit on a bumper sticker but do not advance serious discourse. We ought to resist all of this, and that is possible only if we work to overcome our natural anger at what happened and hatred of those who made it happen.

Finally, let me go back to this entirely counterintuitive, superficially even outrageous idea that people — even terrorists — don’t do what they do out of evil, but because of ignorance. Setting aside the philosophical point that to talk of “evil” as a metaphysical category is highly problematic in itself, I think this attitude — with practice, since it certainly doesn’t come spontaneously — will allow us to see more clearly what is going on and what to do about it.

If we simply label something or someone as evil we give ourselves an automatic pass for not thinking about complexities, root causes, and responsibilities. ISIS exists for a number of reasons, some of which have to do with still widespread perniciously regressive cultures of fundamentalism in the Middle East, but others that have to do with both recent and not so recent Western intervention in that area of the world, often for anything but altruistic reasons.

This does nothing to justify the Paris attacks, but it does a lot for us to understand why they happened and, ideally, what to do to prevent future ones. I am reminded of a controversial editorial written for the Italian magazine L’Espresso by Umberto Eco in the aftermath of the 9/11 attacks on New York’s Twin Towers. The title of the piece was “Understanding Bin Laden.” Eco’s point was precisely the one I’m making here: understanding is an altogether different thing from excusing. There is no condoning either 9/11 or Paris, nor an increasingly large number of similar episodes. But if we do not make a genuine attempt at understanding why so many people think that they are doing the right thing by massacring others in what they see as a necessary defense of their own lands and way of life then we will keep acting unthinkingly, giving in to a simplistic us-vs-them mentality, and simply perpetuate the cycle of violence. As Stoics, Buddhists, Christians, Muslims, and indeed as members of the man cosmopolis, we ought to have the moral courage and the wisdom to do better.