The following are remarks made yesterday by Lewis at the start of his opening lecture in Computer Science 121: “Introduction to Formal Systems and Computation.”

We are beginning the academic year, and its ordinary routine of going to classes and hearing lectures, at an extraordinary moment. Before we jump into the normal business of teaching and learning, I had a couple of thoughts I wanted to share with you. The first is for the short term, how we all act in this community over the next few days. The other is more for the long term.

The level of the devastation and death resulting from Tuesday’s tragedy is so great that, in a class this size, there is almost certainly someone who has lost a relative or friend. There are probably students here today who today simply do not know what has become of people they know and love. In my own office there are two people who have a close friend or relative who is a New York City firefighter. Both firefighters were unaccounted for when I last heard. I would never have guessed that these people were close to New York City firefighters.

So I hope you’ll try to remember that you have no idea what the people you will encounter over the next few days are going through and are dealing with. The fact that they are here, sitting next to you in class or going about their normal activities beginning the academic year, does not mean they are not worried, or even grieving, about friends and loved ones. The fact that we all are trying to maintain a normal routine is not disrespectful to the dead and the wounded. I hope you will to remember these things with everyone you encounter—the woman who swipes your card in the lunchline, the TF to whom you want to complain about a bad grade, the person who has taken too long to answer some e-mail request you have made. You don’t know what they are thinking and what they are experiencing. I hope we can all make an effort just to be a bit kinder than usual at this horrible moment—if someone smiles at you, try to return the smile rather than averting your eyes, if someone grouches at you, try to be forgiving rather than reactive.

The other thought is for the longer run. The one experience in my own life that resembled what we have all been going through over the past few days was when President John F. Kennedy was assassinated. I was about 16. We had the same experience of everyone being collectively and publicly stunned, silent, disbelieving; people wandered around outside with blank stares. We felt that our national security and personal safety were suddenly at serious risk, in a way that had been unthinkable. We were bewildered, and did not know if this was but the beginning of a full-scale foreign attack. And yet there was no smoke in the air in Boston, classes and homework assignments and traffic jams and weather forecasts all were going on as normal.