A Poet of Science


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Aharon Katzir
The link between science and morality is a leading theme in Prof. Aharon Katzir’s book In the Crucible of Scientific Revolution, published just months before he was murdered in a terrorist attack at Ben-Gurion Airport 40 years ago. Katzir believed that scientists hold a multi-faceted responsibility toward society: “Science has ceased being of interest to professionals alone; it has become an enormous societal force whose impact on society’s structure, on people’s interactions and on international politics cannot be ignored.” Throughout his life, Katzir remained faithful to his own credo: In conducting versatile studies, he searched for scientific truth while staying committed to the State of Israel and to humanity at large.

Katzir was born in Poland in 1913 into the Katchalsky family. (He Hebraized his name in the 1950s when he was sent to the Soviet Union on a scientific mission at David Ben-Gurion’s request, thus becoming one of the first Israeli scientists to cross the Iron Curtain). Immigrating to Eretz-Israel with his parents at age 12, he lived in Jerusalem and later studied biology and chemistry at the Hebrew University, enrolling in 1932 with the university’s first generation of students in the natural sciences. In addition to science, he was committed to public activity, and he co-founded a socialist youth movement while a student. During the War of Independence, he worked toward strengthening the young country’s security in parallel with conducting scientific research as a newly minted Ph.D. at the Hebrew University. He co-founded the science corps of the Israel Defense Forces, Hemed, which helped win the war and subsequently served as the basis for Israel’s security industries.

In 1948, Dr. Chaim Weizmann invited Aharon Katzir and his brother Ephraim to join the Weizmann Institute, then in advanced stages of planning. Ernst David Bergmann, the emerging institute’s scientific director, said years later that he had been fascinated by Aharon when he came to Rehovot to discuss the possibility of serving as a department head at the Weizmann Institute: “Some people thought he was too young to assume such a responsibility, but who could resist the charm of a young scientist, brimming with plans and ideas while searching for an enterprise he could build from scratch?”


Katzir in his lab, 1972


Katzir founded the Institute’s Department of Polymers and headed it until his assassination. In his scientific research, he strove to understand the basic processes of life. He chose to study the function of large synthetic molecules, particularly those whose behavior could shed light on major phenomena in living systems. This research led him to the new field of mechanochemistry, which addressed the conversion of chemical energy into mechanical energy, much like the processes taking place in our muscles. Katzir received worldwide recognition for his work in this field.

In one of his last scientific undertakings, Katzir used the theory of thermodynamics of irreversible processes in order to develop a mathematical theory that described the permeability of biological membranes – one of the central issues in physiology and life in general. This mathematical theory was soon accepted by researchers throughout the world. Some of its principles, today considered classic, are still being applied worldwide in science and industry – for instance, in designing membranes for desalination. This work won Katzir and his former student Prof. Ora Kedem the Israel Prize in 1961.

Katzir contributed a great deal to placing Israel on the map of world science. He was among the first Israelis to hold senior posts in international scientific organizations, including President of the International Union for Pure and Applied Biophysics. He was a member of three scientific academies in the United States and received honorary degrees from numerous universities in different parts of the world.
(l-r) Profs. Ephraim and Aharon Katzir, date unknown
In Israel, alongside his basic research, Katzir helped to found numerous institutions that today form an inseparable part of Israel’s intellectual life. He founded the Israel Academy of Sciences and Humanities and served as its president for six years, until his death. Among others, he was instrumental in the creation of Ben-Gurion University of the Negev, the Van Leer Jerusalem Institute and the Feinberg Graduate School at the Weizmann Institute.

Katzir pioneered the popularization of science in Israel. His World of Science popular lectures on the radio drew enthusiastic listeners. A charismatic teacher, he trained hundreds of students. According to Kedem, his Ph.D. students felt as if they were being inducted into the temple of science. When he visited the Soviet Union in the late 1950s, it was the only time that a lecture by a foreign visitor at the University of Moscow had to be transferred to a larger hall.

In May 1972, Katzir was on his way home after attending several conferences in Europe, including a German-Israeli meeting on membranes he had organized in Göttingen with Prof. Manfred Eigen, Nobel laureate in chemistry. At Ben-Gurion Airport, he and other passengers were attacked by Japanese terrorists. About 100 people were wounded in the shooting; 24 of them died, including Katzir.

Few people know that in his youth, Katzir had seriously considered becoming a poet and was a member of the Eretz-Israel Mandolin Orchestra. His wide-ranging interests encompassed, among numerous others, Judaism, literature, philosophy of science, theories of morality, education and information theory. Prof. Shneior Lifson, his former student, called him “a poet of science.”

Prof. Katzir’s life and work is commemorated in Israel and abroad. At the Weizmann Institute, the Aharon Katzir-Katchalsky Center furthers international scientific cooperation through conferences and the exchange of scientists. “Of particular concern to the Center is the impact of scientific and technological advances on human society,” says its mission statement. All three of Katzir’s children chose to follow in his scientific footsteps: Abraham Katzir, a physicist; Yael Katzir, an anthropologist; and Gadi Katzir, a marine biologist.

Special thanks to Orna Zeltzer, Weizmann Institute Archive.