For many graduate students, one semester of Richard Levins’s population science courses wasn’t enough. Some would repeat a class three times: first to adjust to the difficulty of the subject matter, then to grasp the basics, and finally to absorb the nuances of the intellectual web he wove.
From the leftist politics of his childhood to farming in Puerto Rico to teaching at Harvard University, Dr. Levins drew inspiration from disparate experiences many might never try to connect. In an essay posted on the ecoliteracy.org website, he wrote that when examining something such as a disease outbreak, researchers and scholars should integrate their insights “to confront health, society, and habitat as a whole, in its full complexity.”
The German philosopher Georg Hegel “warned that the truth is the whole,” Dr. Levins wrote. “Of course we cannot really see ‘The Whole.’ But, we can recognize that a problem has to be posed big enough to accommodate an answer.”
Dr. Levins, who had been the John Rock professor of population sciences at the Harvard T.H. Chan School of Public Health, died of congestive heart failure Jan. 19 in the Youville Assisted Living center in Cambridge. He was 85 and had lived in Cambridge since 1975.
During a career that included four decades associated with Harvard, he was among the population scientists and theorists who intertwined genetics, evolutionary biology, and environmental studies. In the early 1990s, he was a cofounder of the Harvard Working Group on New and Resurgent Diseases, which examined how infections emerged as a result of environmental changes, including those wrought by humanity.
Dr. Levins believed politics could never be separated from science, and that was the case with his life. He grew up in a household where, when he was a young boy, an uncle “taught me how to recite the preface to the Communist Manifesto,” he wrote in an essay “Unto the Seventh Generation.”
Upon finishing his studies, he learned that his politics made him unwelcome in academia, and so to avoid fighting in the Korean War he became a farmer in Puerto Rico, the homeland of his wife’s extended family. At one point, Dr. Levins refused to answer questions when he was called before the US House Un-American Activities Committee.
He was elected to the National Academy of Sciences. But in 1974, near the end of the Vietnam War, he wrote a letter to the organization declining to join because its scientists participated in military research and, by extension, US foreign policy. “There is the elitist myth that history is made by the important people who are in the know, which happens to include us,” he wrote, adding: “There is the placid belief that a society which appreciates us so well cannot be all that bad.”
As a professor, Dr. Levins combined ecological theory with agriculture studies, visited Cuba to collaborate with scientists there, and developed a mathematical model for examining how competing species coexist. He wrote or coauthored many articles and books, including “Evolution in Changing Environments” in the 1960s and “The Dialectical Biologist,” a 1985 collection of essays penned by Dr. Levins and his longtime colleague Richard Lewontin, a professor of biology emeritus at Harvard.
“Their thesis is that their philosophy is a valuable aid in the practice and understanding of biology. It is not only that Marxism helps in analyzing the history and sociology of science: If you are a working biologist, they are saying, Marxism will help you to plan and to interpret the results of research,” John Maynard Smith wrote in a London Review of Books review of “The Dialectical Biologist.’’
Smith added that Lewontin and Dr. Levins “argue that their own work has been helped by their philosophy. The claim is not only brave but necessary: I would not take them seriously unless they were willing to make it.”
Dr. Levins was the older of two brothers born to Reuben Levins and Ruth Sackman, and he grew up in Brooklyn, N.Y., as part an extended family of Jewish Communists. “The 1930s were an exhilarating but also a scary time for a communist kid,” he wrote in “Unto the Seventh Generation.”
“I was very aware of fascism (friends of the family were going off to Spain to fight Franco, and my room was also the coatroom for meetings in support of the Abraham Lincoln Battalion),” he wrote. “I knew about concentration camps and anti-Semitic laws and rampages.”
He graduated from Cornell University in 1951 with a bachelor’s degree and moved to Puerto Rico with his wife, Rosario Morales, a New Yorker of Puerto Rican ancestry. They had met at a Communist Party social gathering. “They were sitting around listening to classical music and talking politics,” said his daughter, Aurora Levins Morales of Cambridge. “They were 18 or 19 and they fell in love at first sight.” They were engaged within two weeks and married in 1950.
In Puerto Rico “they raised kids and vegetables,” their daughter said. The family eventually returned to the United States, where Dr. Levins received a doctorate in zoology from Columbia University in 1965. They lived again in Puerto Rico, and he taught at the University of Puerto Rico before switching to the University of Chicago, where he stayed until he joined the Harvard faculty in the mid-1970s.
Dr. Levins had three children with Rosario Morales, a writer who died in 2011, and who coauthored “Getting Home Alive” with their daughter in 1986.
Although in some respects Dr. Levins was as well-known for his politics as he was for his science, “one of the most important things he said to me is that there are no bad people, there are only bad choices,” his daughter said. “He didn’t really believe in enemies, even though he took fierce stands for his positions. He didn’t think any human being was bad.”
She added that “everybody talks about his brilliance. He was a really original thinker, but over and over what people talk about is his kindness and his genuine curiosity about everyone and everything.”
A service has been held for Dr. Levins, who in addition to his daughter leaves two sons, Ricardo Levins Morales of Minneapolis and Alejandro Levins of Montague; and five grandchildren.
“One person said he was the sweetest revolutionary he ever met,” Aurora said. “He was very gentle, and even though he was somebody with an international reputation as a scientist, he was incredibly the opposite of arrogant. He never used his prestige in any way. He listened more than he talked and had tremendous respect for other human beings.”
In May 2015, just before Dr. Levins turned 85, friends and colleagues organized “The Truth is the Whole,” a symposium to honor his life, his work, and his politics. The reminiscences of many participants are linked on the symposium’s Harvard School of Public Health website. As a biomathematician and a philosopher of science, Dr. Levins had always worked to bring the obscure into sharp focus, through his teachings and by personal example.
“Biology has become molecular biology and graduates are less likely to tramp through a forest or sniff the earth,” Dr. Levins once said. “They may not even know anything about the animals they study, just the tissue extract. So throughout my career I have encouraged students to look at such things as connections between human activity and forests, and changes in human population and agriculture.”