Yesterday I learned of the passing of Liam Bannon.

Liam was a titan in the field of human-computer interaction (HCI). His work helped to redirect and reorient HCI research in profound and lasting ways. He was an extraordinary intellectual, a deep and open thinker who was able not just to articulate field-changing ideas, but also to help others, myself included, do better work than they could do on their own.

He was also a wit, and was responsible for one of my favorite phrases in HCI, which appeared in his critique of the way HCI treated users as though they were, as he put it, and this is the phrase, “disembodied ratiocinators.” That critique, of course, shifted the focus of HCI, created space for new disciplinary contributions to the field, and made room for thousands of careers, including, much later, my own.

When I first got to know Liam, at a workshop, I noticed he rigorously challenged the presenters, often quietly waiting to go last, so he could put together his most probing thoughts, often upending the conversation that led there. When it was my turn to face him, I was a bit nervous. Rightfully so, because he did take me to task, and to this day I am unsure how well I acquitted myself. It couldn’t have been too badly, because that was the beginning of a decade together of intellectual debates, some collaboration, and friendship. Over the years that I knew him, I increasingly understood that when he took people to task, he was not trying to dominate or show off, but rather he delighted in helping someone to answer a question that they hadn’t even thought to ask.

Several people online have noted his generosity, and rightly so. What I want to add to that is that his generosity was not just about being friendly or well intentioned towards others, but also about giving all of his attention, and his most powerful insights, uncertainties, and reflections, to them. When I shared my best ideas with Liam, he really heard me, and when he challenged me, though sometimes it was tough to take, it truly elevated my thinking. I cannot guess how many scholars he touched in this way, but I do know that it was surely enough to affect the whole field.

More personally, Liam was a friend when I needed one, though it was no easy time for him either, and I am grateful to that final kindness as well.

Well, maybe not quite final: because, and this is totally in character, in our very final exchange, he criticized a book I told him I had been enthusiastically reading. He challenged me to consider a different perspective than I had thus far, making me a more thoughtful reader.

There is, then, a bit of Liam in me, and in, I think, many (if not all) of you who read this. I hope that we may perpetuate that excellence which is now a part of ourselves.

And as I do, I thank Liam.