Richard Friederich Arens, who made fundamental contributions to many areas of mathematics and mathematical physics, and who was the managing editor of the Pacific Journal of Mathematics for many years, passed away on May 3, 2000. His many friends and colleagues from UCLA and the Pacific Journal mourn his passing away, and remember him as a wonderful human being, full of charm and wit, serene till the end, and above all, a great master of mathematics.

Arens was born in Germany in 1919 and emigrated to the United States in 1925. He attended public schools in Pasadena, California and enrolled at the University of California Los Angeles in 1937. In 1940 Arens won a full scholarship to Harvard University by placing first in the national William Lowell Putnam mathematics competition for college students. After his Ph.D at Harvard under Garrett Birkhoff, Arens went to the Institute for Advanced Study at Princeton as an assistant to Marston Morse. In 1947 he joined the department of mathematics at UCLA. He served with distinction till his retirement in 1989. His work on functional analysis, on Banach algebras and their deep connections with several complex variables, on relativistic particle interactions, on geometric quantization, on Noether currents and other differential geometric aspects of classical field theories, became widely known and established him as a mathematician of the first rank.

He became a member of the editorial board of the Pacific Journal in 1965 and was formally named as the managing editor in 1973, a position he held until 1979. It was during his long stewardship during the years 1965–79 that the Pacific Journal grew out of its local roots and became an internationally recognized mathematics journal of distinction and quality. This transformation of the Pacific Journal was almost entirely due to his broad vision and the unlimited energy with which he looked after the Journal. Even after he left the managing editorship his advice was always available for and eagerly sought after by his successors. His way of running the Journal was relaxed, but there was no compromise with quality. In his dealings with authors, referees, editors and others connected with the operation of the Journal, he was gentle, often humorous, never condescending, and above all, completely human.

The range and depth of what he knew and understood, not only in mathematics but outside of it, were truly astonishing. Yet he wore his distinction lightly. During the memorial service held at UCLA in June a friend remarked to me that after we have said everything his personality still remains elusive. He was truly sui generis.