When MIT hired the Dutch mathematician Dirk Jan Struik in 1926, it got an accomplished geometer who had studied with famed mathematician David Hilbert, and a budding historian who had spent two years researching 19th-century mathematics. But the Institute also got an outspoken Marxist—a seemingly insignificant fact that would become a very big deal 25 years later.

Born in 1894 in Rotterdam, Holland, Struik attributed his love of mathematics and history to his schoolteacher father. Specializing in differential geometry—particularly Riemannian manifolds and tensor calculus—he published his first research article four years before receiving his doctorate in 1922, and he remained prolific throughout his life, publishing his last article in 1995—in Technology Review—at the age of 101.

He married Saly Ruth Ramler, the first woman to receive a doctorate in mathematics from the German University in Prague, in 1923. They then spent two years traveling Europe on his Rockefeller Foundation fellowship, studying with some of the world’s most famous mathematicians. Offered jobs at both MIT and what was then called Second Moscow State University, he accepted a position as a “special lecturer” at the Institute in 1926 at the urging of MIT professor Norbert Wiener. He was promoted to assistant professor two years later, and he was an associate professor by 1931. 

After a year’s leave in 1934 to lecture in Mexico, Holland, and the USSR, Struik continued his work on tensor calculus, lecturing to the graduate students and staff of the MIT electrical engineering department in 1937; he was also invited to give a course on differential geometry at Harvard. Struik was named a full professor in 1940. 

He continued his historical research as well. In 1948 he published A Concise History of Mathematics, an authoritative two-volume set that includes many of the early contributions from Egypt, China, India, and the Arab world. It was translated into more than 17 languages, and the fourth revised edition is still in print today. (He would later be hailed as “the instructor responsible for half the world’s basic knowledge of the history of mathematics.”) The same year, he also published Yankee Science in the Making, a survey of New England’s science and technology from the colonial era through 1861, which remains an important work in the field.

Struik told journalists that he was a “Marxist in the broadest sense,” but he denied being a member of the Communist Party.

Things were going well for Professor Struik, but his world was about to change.

In July 1948 the US Department of Justice filed charges against 12 senior leaders of the Communist Party of the United States of America for violating the Alien Registration Act. Better known as the Smith Act, the 1940 law made it a crime to advocate the violent overthrow of the US government. 

The trial started in January 1949 and ran for months. The first major witness was Louis Budenz, a CPUSA leader turned informant. Next came a surprise witness: Herbert A. Philbrick, a 33-year-old advertising executive for a Boston-area movie theater chain who had secretly been a dues-paying member of the Massachusetts Communist Party for nine years—and, even more secretly, a spy for the FBI.

Philbrick had been organizing the Cambridge Youth Council in 1940 when he started receiving Communist literature. He contacted the FBI and was encouraged to infiltrate Communist groups. He was even given money to rent audio equipment to dictate his reports. 

On the witness stand, Philbrick claimed the party was teaching “violent revolution to be carried out by bands of armed workers against the existing state government.” These efforts would be aided by party members who would infiltrate key industries, a practice known as “colonizing,” he said.

Near the end of his testimony on April 8, Philbrick “made one more startling disclosure,” reported Time magazine: “One of the teachers at the secret schools for revolutionists was none other than Dirk Struik, professor of mathematics at the Massachusetts Institute of Technology, longtime sponsor of many organizations listed as subversive.”

Struik had avoided political activity when he first arrived in the US but proudly participated in what he later called “the struggle for what I saw as social justice” after he was naturalized in 1935. He had indeed helped fund Boston’s Samuel Adams School for Social Studies, a Communist school modeled after the Jefferson School of Social Science in New York City; he also wrote for the Marxist publication Science and Society and was active on the National Council of American-Soviet Friendship. At one meeting in Cambridge in 1947 that Philbrick attended, Struik had presented a review of Lenin’s State and Revolution.

Struik told journalists that he was a “Marxist in the broadest sense,” but he denied being a member of the Communist Party. In fact, as required by state law, he had taken an oath pledging to support both the US and Massachusetts constitutions.

In a meeting with MIT president James R. Killian, Struik said that he taught only mathematics at MIT, never political ideology. Killian agreed, saying that on several occasions the Institute had placed “observers” in Struik’s classroom and none had reported hearing anything improper.

In May 1949 Killian issued a three-page statement reading in part, “The Institute believes that Professor Struik, who denies that he has committed any crime, should be considered innocent of any criminal action unless he is proved guilty.” 

On July 24, 1951, Struik was called before the House Un-American Activities Committee (HUAC). He briefly attempted to explain that he was a Marxist but not a Communist and then refused to answer most of the committee’s questions, including whether he was or had ever been a member of the Communist Party, citing his Fifth Amendment right not to incriminate himself. The story was front page news in the Boston Globe.

On September 12, 1951, a Middlesex County grand jury indicted Struik for “conspiracy to overthrow the governments of the United States and Massachusetts, and for advocating the overthrow by violence of the government of the Commonwealth of Massachusetts,” the Globe reported. He was released on $10,000 bail. 

The MIT faculty held a hasty and sparsely attended meeting that afternoon—the fall term hadn’t started—and voted to suspend Struik with full pay until the case was resolved. But beyond Philbrick’s testimony, at that point there was no evidence that Struik was anything beyond a mathematician with a fondness for Marxism and social justice—hardly grounds for firing. Karl Taylor Compton, Class of 1908, SM 1909, PhD 1912, chairman of the MIT Corporation and a former MIT president, defended keeping him on the payroll, noting: “As an institution we did not feel justified in taking action on the basis of rumors and charges that no one could substantiate.” And Rosalind Williams, professor emeritus in the Program on Science, Technology, and Society, recalls that her grandfather, chemical engineering professor Warren K. Lewis, told her MIT believed that only the Institute should decide if he was worthy of a faculty appointment. 

“More than once he told me that when the McCarthyites set their sights on Struik, MIT mounted a vigorous defense, partly supported by lawyers who went back to medieval canon law to establish the principle that only fellow monks could make the decision to expel a monk,” she says. “He said this with pride in MIT for defending Struik on principle.” 

Struik wanted a speedy trial, but his case was delayed because the district attorney wanted to try him together with Melrose businessman Harry E. Winner and Margaret Gilbert of Cambridge, a founder and former executive secretary of the Samuel Adams School, who both faced similar charges. And Gilbert was in Chicago, fighting extradition to Massachusetts.  

More evidence came to light in April 1953, when the head of the MIT mathematics department, William Ted Martin, testified before HUAC that he’d been a member of an MIT communist cell that included Struik between 1938 and 1946. In September, the Illinois Supreme Court ruled that Gilbert should be returned to Cambridge, yet the trial was still pending in June 1954, when “a hoodlum band” burned crosses on Struik’s lawn and set fire to his house. (It was quickly doused by a neighbor with a garden hose.) 

The case would soon fall apart. Struik, Winner, and Gilbert had been accused of violating the Massachusetts Anti-Anarchy Act. In a similar case in Pennsylvania, a defendant appealed his conviction under the Pennsylvania Sedition Act, arguing that the federal Smith Act superseded the state act. In April 1956 the US Supreme Court agreed, and threw out the conviction. In May 1956 the Massachusetts Supreme Judicial Court concluded that the Massachusetts law was similarly invalid. The Massachusetts indictments were thrown out, and MIT president James R. Killian allowed Professor Struik to resume teaching. 

In October 1956, MIT’s executive committee announced that it was sustaining Struik’s tenure but formally censuring him after a four-month investigation. A faculty committee deemed his use of the Fifth Amendment “conduct unbecoming an institute professor” and said it showed a lack of candor on his part. Its report said that though Struik’s activities embarrassed the Institute, “the Committee does not believe … that relief from embarrassment should justify action against him which might stand as a serious breach in the Institute’s commitment to freedom of inquiry, discussion, and action.” 

Required, like all professors at the time, to retire at 65, Struik became a visiting professor at the University of Puerto Rico in 1962 and later at the University of Utrecht, where he was in charge of the Institute for the History of the Exact Sciences. In 1969 he was made a member of the International Academy of the History of Sciences.

Struik lived to the age of 106. At a celebration of his 100th birthday, he attributed his longevity to the “3Ms: marriage, mathematics, and Marxism.”  

“Mathematicians grow very old; it is a healthy profession,” he said. “The reason you live long is that you have pleasant thoughts.”