Professor Emeritus Dirk J. Struik, a highly respected analyst and geometer and an internationally acclaimed historian of mathematics, died at his home in Belmont on Saturday. He celebrated his 106th birthday on September 30.

Professor Struik was a member of the MIT mathematics faculty from 1928 until 1960, and remained intellectually active throughout his life.

Beginning in 1912, Professor Struik was educated very broadly in mathematics and physics at the University of Leiden, taking courses from Lorentz and de Sitter. After a short interruption (for lack of funds), he was invited by J. A. Schouten to do research on tensor analysis and differential geometry. It was during this time that he met and soon married Saly Ruth Ramler, a Czech mathematician and accomplished modern dancer. Dr. Ramler wrote her doctorate on the axiomatics of affine geometry under G. Pick and G. Kowalewski at the University of Prague in 1918, and as Professor Struik later wrote, "Ruth may well have been the first woman at the more than 500-year-old university to receive a doctorate in mathematics."

With a stipend from a Rockefeller Fellowship, the Struiks moved to Rome and then to Gï¿½ï¿½ttingen, which was becoming a major mathematical center. There they met and worked with Cartan, Courant, Hilbert, Landau and Noether, among others. Professor Struik also collaborated with MIT Professor Norbert Wiener, who in the spring of 1926 offered him a lectureship beginning that fall.

Professor Struik's long and successful career in differential geometry led to a great many mathematical papers and books, including the 1950 text Lectures in Classical Differential Geometry. He had been interested since spending time in Rome in the history of mathematics. In 1948 he published A Concise History of Mathematics, Volumes I & II and Yankee Science in the Making. One reviewer of the first book said that "the author takes care to distinguish between established facts, plausible theories, wild hypotheses and traditional ideas."

In a centennial tribute to Professor Struik in 1994 by the Dibner Institute for the History of Science and Technology, Executive Director Evelyn Simha said: "As an historian of mathematics, he is particularly important to us here at this center for advanced research in the history of science and technology, because of his great and influential book, A Concise History of Mathematics, beautifully balanced between technicalities and generalities, translated into uncountable languages, most recently Persian. With this book and his historical scholarship, Struik has become the instructor responsible for half the world's basic knowledge of the history of mathematics."

Professor Struik held an abiding interest in Marxism. Following World War II and into the McCarthy period, his political views attracted attention, and in September 1951 he was indicted by a Middlesex County Grand Jury on charges of advocating the overthrow of the United States and Massachusetts governments. At the time of the indictment, MIT suspended Professor Struik from teaching duties with full pay and benefits until the case could be dealt with in the courts. After five years, the charges were dropped without trial, due to lack of evidence and a US Supreme Court ruling that states do not have jurisdiction in such matters.

In May 1956, MIT President James R. Killian Jr. reinstated Professor Struik. The following October, acting on the recommendations of a faculty review committee, the MIT Corporation's executive committee upheld the restoration of Dr. Struik's tenure but censured him "for conduct unbecoming" an MIT professor, based largely on his use of the Fifth Amendment before the House Un-American Activities Committee and "his comparative lack of candor with members of the administration."

On this subject, Dibner Institute Executive Director Evelyn Simha noted in her 1994 tribute: "From the very beginning, personally and professionally, and continuing even now, Professor Struik's great concern for people in oppressed situations has been the backdrop for all his activities, has informed his life and work in fact, even when it brought him hard times." Later, she added: "He wanted to link mathematics with the socio-economic background against which mathematics developed, questioning the weight of social and economic forces in the development even of the 'pure math' of the Greeks, for example. He is now interested in ethno-mathematics and remains unshaken in his social and political beliefs."

Professor Struik continued his scholarly and teaching work after his retirement in 1960. In 1975 he was awarded a Gold Medal of Achievement by the National University of Mexico "for his services to the teaching and development of mathematics in Mexico over the years." In March and April that year, Professor Struik gave a series of lectures on the History of Mathematics to the MIT Concourse Forum. In Hamburg, Germany, in May 1989, he was awarded the first Kenneth Ownsworth May Prize for outstanding contributions to the history of mathematics by the International Commission on the History of Mathematics & International Union of the History and Philosophy of Science.

Born in Rotterdam in the Netherlands, Professor Struik was educated at the University of Leiden in Holland, where he received his doctorate in 1922. He was an assistant at the Technical University in Delft from 1917 to 1924, and an International Education Fellow in Italy and Germany from 1924 to 1926.

He came to MIT in 1926 as a lecturer in mathematics and was appointed an assistant professor in 1928. He was promoted to associate professor in 1931 and professor in 1940. He became an American citizen in 1934. He retired from MIT in 1960 as Professor Emeritus of Mathematics. In 1972 he was made an honorary research associate in the History of Science Department at Harvard University.

Asked what he missed most when he turned 100, Professor Struik said simply, "My wife." Dr. Ramler, his wife of 70 years, died in 1993 at the age of 99.

Professor Struik is survived by three daughters, Ruth Rebekka Struik, a mathematics professor emerita at the University of Colorado; Anne Macchi of Arlington, MA, a retired teacher; and Gwendolyn Bray of New Zealand, an ecologist; 10 grandchildren and three great-grandchildren. A memorial will be scheduled by the Department of Mathematics.

*A version of this article appeared in MIT Tech Talk on October 25, 2000.*