Joseph Weizenbaum

Joseph Weizenbaum, professor emeritus of computer science at MIT who grew skeptical of artificial intelligence after creating a program that made many users feel like they were speaking with an empathic psychologist, died March 5 in Berlin. He was 85.

Weizenbaum, who was Jewish, fled Nazi Germany with his parents and arrived in the United States in the mid-1930s. At the beginning of his career with computers, in the early 1950s, he worked on analog computers; later, he helped design and build a digital computer at Wayne University in Detroit, Mich.

In 1955, Weizenbaum became a member of the General Electric team that designed and built the first computer system dedicated to banking operations. Among his early technical contributions were the list processing system SLIP and the natural language understanding program ELIZA, which was an important development in artificial intelligence and cemented his role in the folklore of computer science research.

Named for the heroine of My Fair Lady, ELIZA was perhaps the first instance of what today is known as a chatterbot program. Specifically, the ELIZA program simulated a conversation between a patient and a psychotherapist by using a person’s responses to shape the computer’s replies. Weizenbaum was shocked to discover that many users were taking his program seriously and were opening their hearts to it. The experience prompted him to think philosophically about the implications of artificial intelligence, and, later, to become a critic of it.

In 1976, he authored Computer Power and Human Reason: From Judgment to Calculation, in which he displayed ambivalence toward computer technology and warned against giving machines the responsibility for making genuinely human choices. Specifically, Weizenbaum argued that it was not just wrong but dangerous and, in some cases, immoral to assume that computers would be able to do anything given enough processing power and clever programming.

“No other organism, and certainly no computer, can be made to confront genuine human problems in human terms,” he wrote.

Computer Power and Human Reason raised questions about the role of artificial intelligence, and spurred debate about the role of computer system reliance on them example of how man relies on technology in order to escape the burden of acting as an independent agent,” Weizenbaum told the journal. “It helps him avoid the task of giving meaning to his life, of deciding and pursuing what is truly valuable.”

Weizenbaum joined MIT in 1963 as a visiting associate professor of computer science. Within four years, he had been awarded tenure in the Department of Electrical Engineering. He later held academic appointments at Harvard University, at the Harvard Graduate School of Education, Stanford University, the Technical University of Berlin and the University of Hamburg in Germany. He was a fellow of the American Association for the Advancement of Science, a member of the New York Academy of Science and of the European Academy of Science.