Creator of Fuzzy Logic
Lotfi Zadeh in his office at Berkeley. September 1994.
Lotfi Zadeh was born in Baku, Soviet Azerbaijan, in 1921; today, his scientific concept, Fuzzy Logic, has strongly impacted computer technology, tomorrow it may be shaping the way we perceive the world. Back in 1965 when you published your initial paper on Fuzzy Logic, how did you think it would be accepted? Well, I knew it was going to be important. That much I knew. In fact, I had thought about sealing it in a dated envelope with my predictions and then opening it 20-30 years later to see if my intuitions were right. I realized this paper marked a new direction. I used to think about it this way-that one day Fuzzy Logic would turn out to be one of the most important things to come out of our Electrical Engineering Computer Systems Division at Berkeley. I never dreamed it would become a worldwide phenomenon. My expectations were much more modest.
Lotfi Zadeh (2nd from right) returned to visit Azerbaijan, his country of birth, in 1967. Here he is seen with officials at the Azerbaijan Oil Institute. In 1993, the Azerbaijan Academy of Oil honored Lotfi with an Honorary Professorship.
How did you think Fuzzy Logic would be used at first? In many, many fields. I expected people in the social sciences-economics, psychology, philosophy, linguistics, politics, sociology, religion and numerous other areas to pick up on it. It's been somewhat of a mystery to me why even to this day, so few social scientists have discovered how useful it could be. Instead, Fuzzy Logic was first embraced by engineers and used in industrial process controls and in "smart" consumer products such as hand-held camcorders that cancel out jittering and microwaves that cook your food perfectly at the touch of a single button. I didn't expect it to play out this way back in 1965. How did you come up with the term, "Fuzzy Logic"? I coined the word "fuzzy" because I felt it most accurately described what was going on in the theory. I could have chosen another term that would have been more "respectable" with less pejorative connotations. I had thought about "soft", but that really didn't describe accurately what I had in mind. Nor did "unsharp", "blurred", or "elastic". In the end, I couldn't think of anything more accurate so I settled on "fuzzy". Would you say that Fuzzy Logic turns Aristotelian or Classical Logic on its head? (Laughs). Back in Aristotle's day, people tried to be as precise as possible. That's the Aristotelian tradition, the Cartesian tradition. Looking at things as being entirely black or white stems from such a tradition. But take the example of good and bad. What we're beginning to understand now is that sometimes things that we perceive as bad really turn out to be good, or perhaps, not as bad as we originally thought. Things can serve a purpose. People back in Aristotle's time and even later thought that by perceiving things in black and white (in absolute terms) that they gained alot. And they did. But they lost a great deal in the process. Fuzzy Logic represents a swing in the opposite direction but I would like to stress that there is much more to Fuzzy Logic than multi-valuedness of truth. How could they ignore it? When the only tool you have is a hammer, everything begins to look like a nail. Classical logic simply doesn't provide the means to solve the problems. They concerned themselves with models of precise knowledge. But such models are so far removed from the real world that they don't do you any good. Why are you so "down to earth" in your own approach to solving problems? I'm that kind of person. I've been conscious for a very long time that the real world is very complex. There's always a tendency to oversimplify. That was the case in physics. In my youth, we had very simple models. About electrons in orbit. About protons. Models of the solar system. Of course, today we realize that these were ridiculous. The physics of these phenomena are infinitely more complex. Why is Fuzzy Logic described as "cheaper" and "easier" than traditional methods of computing? Fuzzy Logic is "coarse". The important thing about Fuzzy Logic is that it's done in a "coarse" way-not refined. Anything that is coarse-grained is simpler and cheaper. If, for example, you want to park a car and somebody said, you had to do it within ±1/10 of an inch of some particular point, you'd be in trouble. The reason why people can do things like park a car is that they don't have to be very specific to succeed. Everybody is talking about the Japanese being so advanced in Fuzzy Logic. Is that true? It's true. The Japanese are very consumer oriented. They are incorporating Fuzzy Logic into many of their products, especially appliances and electronic equipment. But I just returned from Germany a few days ago (October 21st) and was very impressed by what is happening there. There are many, many people working on Fuzzy Logic both in industry and the universities. There are many good papers and books. I would say that next to Japan, Germany is the country with the highest level of activity. And where would you place the United States? Third. Russia used to be high up there and there used to be quite a few scientists interested in Fuzzy Logic and a number in Azerbaijan. But with the breakup of the Soviet Union, there's no money for these things now. China is very active, too, isn't it? The Chinese Government used to be very supportive of Fuzzy Logic. Scholars there have written quite a few papers related to traditional Chinese medicine, mathematics and engineering. You often hear a figure of 10,000 Chinese scientists involved with Fuzzy Logic. That figure refers to the activity before the events of Tiennenman Square. The government used to support Fuzzy Logic in a big way back then, but now some of the most active people have left for Singapore and Hong Kong. There seems to be a close correlation between Fuzzy Logic and Linguistics. So much of what is inherent in Fuzzy Logic relates to the way people think and talk-in other words, their use of natural language. What influence did your early exposure to so many different languages play in shaping these attitudes? (Before Zadeh was twelve, he was having to deal with four different languages-Russian, Azerbaijani, Persian, and English-and three separate scripts-Cyrillic, Arabic, and Latin). You're right. The Fuzzy Logic model relates closely to linguistics. But I'm not sure learning these languages had a big influence on my thinking. If it did, then only subconsciously. But I do remember one thing that made a very deep impression on me in my youth. That was how different people could wholeheartedly embrace systems-whether political, religious, social, whatever-that were diametrically opposite. And what about the influence from Azerbaijanis? Obstinacy and tenacity. Not being afraid to get embroiled in controversy. That's very much a Turkish tradition. That's part of my character, too. I can be very stubborn. That's probably been beneficial for the development of Fuzzy Logic. And Russia? Your mother was Russian, wasn't she? From the Russians I gained a great respect for knowledge-a broad based knowledge. I read so many books as a child-Dostoyevsky, Chekhov, Tolstoy. Those books put goodness on a pedestal. The heroes of those books were always fighting evil. You'll find the pursuit of goodness on all their pages, except for Dostoyevsky. I had a library of, maybe, 3,000 books since my father had been a journalist. I read Shakespeare in Russian. There was such a respect for knowledge in my youth. You must be quite pleased to see how the field of Fuzzy Logic has expanded so much in these past 25 years, especially since the late 1980s. I don't feel any different now than I did 15-20 years ago. Somedays, I'm pleased with the progress; sometimes not. C'est la vie! But basically, I don't have an egocentric view of myself. I never felt that I was an important person. I feel ordinary like anybody else. I have no feeling of importance. No such feeling whatsoever. I don't attach very much importance to who I am. Looking back on the development of Fuzzy Logic and its application, what would you have done differently to promote your ideas? I've made no effort to go after scientists or companies to show them how my theories could be applicable to their work. I don't promote this thing. If people want to do something, that's fine. If they don't, that's fine, too. What kinds of applications have you been excited to see develop? I can't say that anything has been "exciting". Rather, I would choose the word "interesting". Not too long ago, the Chinese University of Hong Kong conducted a survey to determine which consumer products were using Fuzzy Logic. The result was a thick report, some 150-200 pages long-washing machines, camcorders, microwave ovens, etc. What interested me wasn't the particular applications so much as the breadth of applications-so many products were incorporating Fuzzy Logic. What would be the ultimate application of Fuzzy Logic? I can't say that I have much time to think much about such things because I have to focus on more immediate deadlines-like this speech I'm giving in New York to a Semantics group on November 4th (one week from now). I tend to think about things closer to the present. I have to do quite a bit of thinking about those things; if I didn't, I'd soon sound like a broken record and they wouldn't invite me to these conferences. I always feel like I have to say something different than what I've said before. What's the future for Fuzzy Logic? In general, I think the future will involve fuzzy logic, neural networks and genetic algorithms. I lump all these under the rubric of "soft computing". I'd encourage people who have the inclination and ability to become competent in all three of these areas. Eventually, I believe that Fuzzy Logic will have a wide-ranging impact once it is understood how widely the theory can be applied. Of course, this is just my opinion; only time will tell. |
|