by George G. Roussas
I joined the Department of Statistics at the University of California, Berkeley (UCB) in the spring semester 1960, after having graduated with a degree in mathematics from the University of Athens, Greece, and having served my two-year military service in the Greek army.
David Blackwell was the chair of the department at that time, and Lucien Le Cam was the graduate advisor. Blackwell would have a brief interview with every incoming graduate student, and it was in this capacity that I first met him. Right after my interview with him, a couple of other, also new, graduate students pointed out to me that we had a black man as chair of the department. In a way, I was taken by surprise, and I responded “come to think of it, we certainly do!” Professor Blackwell’s personality was overwhelmingly strong and yet gentle and enchanting, radiating kindness around him. These attributes transcended any trivialities such as noticing the color of his skin. Besides, my cultural background was alien to it.
The UCB campus was an earthly paradise, and the faculty of the department were like Olympian figures to me in the statistics pantheon. I had the utmost respect and admiration for all and each one of them.
Nevertheless, some did stand out, as it were. Thus it was the grand old man Jerzy Neyman from whom, foolishly, I never took a course. He was nice to me, and more than once he recounted his experiences in Greece as a member of a certain commission soon after World War II. It was Michel Loève from whom I took my first course in probability and who inspired me with rigor and deep interest in the subject matter. Later, I also took his year-long course in probability and stochastic analysis. It was the mathematician-philosopher Edward Barankin from whom I learned measure-theoretic probability, and I was also introduced to time series analysis and sufficiency. It was Lucien Le Cam from whom I managed to chip away bits of his vast knowledge of asymptotics in statistics. They were destined to play a formative role in my academic career.
And it was David Blackwell who was destined to be my thesis advisor under some peculiar circumstances.
If I remember well, it was in the early 1960s that Lester Dubins was offering a seminar based on his book (coauthored with Jim Savage) How to Gamble if You Must: Inequalities in Stochastic Processes. Blackwell was attending that seminar, as well as a fair number of students, including myself. At the end of each lecture, Blackwell would suggest a number of open questions for possible thesis topics. It was such a question that he brought to my attention and insisted that I look into. Indeed, I did, and in a couple of months I asked for an appointment with him to report accordingly. At that time, he was advising a large number of students, and his appointments were limited by necessity to a half-hour block of time. Apparently, he was pleased by what he read, was very encouraging, and also made a number of concrete suggestions. After another couple of sessions like this, he decided that the solution that I arrived at was what he expected. Encouraged by this, I asked whether I could combine this piece of work with another paper on asymptotics, which was already accepted for publication in the Annals of Mathematical Statistics, to make up my thesis. Blackwell’s response was as always brief and clear-cut. “To me, this by itself is more than enough.”
And that is how I had the privilege and honor to be David Blackwell’s student.
From the courses I took from him (one in game theory and the other in coding/information theory) I saw firsthand how a great scientist can also be an inspiring and superb teacher. From my interaction with him, as his advisee, I could not help but admire the clarity of his thoughts, articulated in an amazingly brief and simple way. At the same time, his polite disposition and abundant kindness had absolutely no match.
Soon after I was conferred my Ph.D. degree in 1964, I had the opportunity to host a dinner party for Professor and Mrs. Blackwell in a rather original and upscale restaurant in the Bay area (I believe it was called the Nero’s Nook), located in the Los Gatos area. It was apparent that all three of us had a truly enjoyable time.
After I moved to the University of Wisconsin–Madison (UWM), the first time that I met him was in 1972 during the Sixth (and last) Berkeley Symposium in Statistics and Probability. The next ten years or so I spent overseas, at the University of Patras, Greece, and I more or less lost contact with him except for a Christmas card. In 1984 I dropped by UCB after I returned to the West Coast (at the University of California, Davis). In Berkeley, I had the opportunity to have lunch with Edward Barankin (in the restaurant of the Durant Hotel), who, unfortunately, succumbed to cancer soon thereafter. David Blackwell received me very warmly and invited me for lunch at the canonical fish restaurant in Berkeley (Spenger’s Fresh Fish Grotto). Also, he expressed his satisfaction that one of his old students did fairly well as a senior faculty member now (full professor at UWM and chair of applied mathematics at the University of Patras) and also as an academic administrator (dean of the School of Physical and Mathematical Sciences at Patras and also chancellor of the same university). However, for me, David Blackwell remained “Professor Blackwell” as an expression of my utmost respect for him and also because of my European early upbringing. But this would not do anymore for Blackwell. On the spot he put me in a difficult dilemma; “Either you call me David or I will never talk to you again!” So, Professor Blackwell became David for me henceforth.
Once at UCD, I was given the opportunity to drop by UCB, but not as often as I would have liked. From what remained of the old guard, Blackwell and Le Cam were the people that I would always visit.
It was in early June 2010 when we received an email message at UCD from Bin Yu, the current chair of the Department of Statistics at UCB, that David was not doing well. I was about to depart for the annual pilgrimage to Greece (on June 13), but I did make a concerted effort to obtain a brief visit with David before my departure. That effort was not successful. I resolved to try again soon after my return (July 7). Unfortunately, that effort never came to be; David Blackwell departed on July 8.
His memory will remain alive among all those who were fortunate enough to know him and to profit from his wisdom and his gentle and kind disposition. For me, David Blackwell was and will remain the role model of a great mathematician, an inspiring teacher, and a superb human being.
