Silent Spring, Rachel Carson’s landmark warning about the indiscriminate use of pesticides, turns 50 this month. By extension, that puts the environmental movement also at the half-century mark—along with the bitter, divisive argument we continue to have over both the book and the movement it spawned. The terms of that argument, which emerged in the brutal reaction to Silent Spring from those who saw it not as a warning but as a threat, haven’t changed much. And they leave us with a vexing question: Why do we fight? How is it that the environment we all share is the subject of partisan debate? After all, the right and the left inhabit the same planet, even if it doesn’t always seem that way.

Carson’s book was controversial before it even was a book. In June 1962, three long excerpts were published by The New Yorker magazine. They alarmed the public, which deluged the Department of Agriculture and other agencies with demands for action, and outraged the chemical industry and its allies in government. In late August 1962, after he was asked about pesticides at a press conference, President Kennedy ordered his science adviser to form a commission to investigate the problems brought to light, the president said, by “Miss Carson’s book.” A month later, when Silent Spring was published, the outlines of the fight over pesticides had hardened. Armed with a substantial war chest—Carson’s publisher heard it was $250,000—pesticide makers launched an attack aimed at discrediting Silent Spring and destroying its author.

The offensive included a widely distributed parody of Carson’s famous opening chapter about a town where no birds sang, and countless fact-sheets extolling the benefits of pesticides to human health and food production. Silent Spring was described as one-sided and unbalanced to any media that would listen. Some did. Time magazine called the book “hysterical” and “patently unsound.”

Carson’s critics pushed her to the left end of the political spectrum, to a remote corner of the freaky fringe that at the time included organic farmers, food faddists, and anti-fluoridationists. One pesticide maker, which threatened to sue if Silent Spring was published, was more explicit: Carson, the company claimed, was in league with “sinister parties” whose goal was to undermine American agriculture and free enterprise in order to further the interests of the Soviet Union and its Eastern European satellites. The word Communist—in 1962 the most potent of insults—wasn’t used, but it was understood. Silent Spring, said its more ardent detractors, was un-American.

And there the two sides sit 50 years later. On one side of the environmental debate are the perceived soft-hearted scientists and those who would preserve the natural order; on the other are the hard pragmatists of industry and their friends in high places, the massed might of the establishment. Substitute climate change for pesticides, and the argument plays out the same now as it did a half-century ago. President Kennedy’s scientific commission would ultimately affirm Carson’s claims about pesticides, but then as now, nobody ever really gives an inch.

Carson was also accused of having written a book that, though it claimed to be concerned with human health, would instead contribute directly to death and disease on a massive scale by stopping the use of the insecticide DDT in the fight against malaria. One irate letter to The New Yorker complained that Carson’s “mischief” would make it impossible to raise the funds needed to continue the effort to eradicate malaria, and its author wondered if the magazine’s legendary standards for accuracy and fairness had fallen. Apparently unaware of the distinction between science authors and nudists, the letter writer referred to Carson as a “naturist.”

The claim that Rachel Carson is responsible for the devastations of malaria, especially in sub-Saharan Africa, has gained renewed traction in recent years. The American Enterprise Institute and other free-market conservatives have defended the safety and efficacy of DDT—and the claim of Carson’s “guilt” in the deaths of millions of Africans is routinely parroted by people who are clueless about the content of Silent Spring or the sources of the attacks now made against it. The Competitive Enterprise Institute, a limited-government, free-enterprise think tank, maintains the website rachelwaswrong.org, which details Carson’s complicity in the continuing plague of malaria. In 2004, the late writer Michael Crichton offered a bite-sized and easy-to-remember indictment of Carson’s crime: “Banning DDT,” Crichton wrote, “killed more people than Hitler.” This was dialogue in a novel, but in interviews Crichton made it clear this was what he believed.

Rachel Carson, who stoically weathered misinformation campaigns against her before her death from breast cancer in 1964, would find the current situation all-too predictable. As she said once in a speech after the release of Silent Spring, many people who have not read the book nonetheless “disapprove of it heartily.”

Rachel Carson never called for the banning of pesticides. She made this clear in every public pronouncement, repeated it in an hourlong television documentary about Silent Spring, and even testified to that effect before the U.S. Senate. Carson never denied that there were beneficial uses of pesticides, notably in combatting human diseases transmitted by insects, where she said they had not only been proven effective but were morally “necessary.”

“It is not my contention,” Carson wrote in Silent Spring, “that chemical insecticides must never be used. I do contend that we have put poisonous and biologically potent chemicals indiscriminately into the hands of persons largely or wholly ignorant of their potentials for harm. We have subjected enormous numbers of people to contact with these poisons, without their consent and often without their knowledge.”

Many agreed. Editorializing shortly after The New Yorker articles appeared, the New York Times wrote that Carson had struck the right balance: “Miss Carson does not argue that chemical pesticides must never be used,” the Times said, “but she warns of the dangers of misuse and overuse by a public that has become mesmerized by the notion that chemists are the possessors of divine wisdom and that nothing but benefits can emerge from their test tubes.”

Carson did not seek to end the use of pesticides—only their heedless overuse at a time when it was all but impossible to escape exposure to them. Aerial insecticide spraying campaigns over forests, cities, and suburbs; the routine application of insecticides to crops by farmers at concentrations far above what was considered “safe;” and the residential use of insecticides in everything from shelf paper to aerosol “bombs” had contaminated the landscape in exactly the same manner as the fallout from the then-pervasive testing of nuclear weapons—a connection Carson made explicit in Silent Spring.

“In this now universal contamination of the environment,” Carson wrote, “chemicals are the sinister and little-recognized partners of radiation in changing the very nature of the world—the very nature of its life.”

The Competitive Enterprise Institute—to its credit—acknowledges that Carson did not call for the banning of pesticides in Silent Spring. But they claim Carson’s caveat about their value in fighting disease was so overwhelmed by her general disapproval of their use that “negative publicity” around Silent Spring halted the use of DDT against malaria, notably in sub-Saharan Africa, where some 90 percent of the world’s malaria cases occur.

It’s true that Carson found little good to say about DDT or any of its toxic cousins—the chlorinated aromatic hydrocarbon insecticides developed in the years after World War II and after the Swiss chemist Paul Muller had won a Nobel Prize for discovering DDT. But it’s a stretch to see how the mood surrounding Silent Spring was the prime cause of DDT’s exit from the fight against malaria. And, as the New York Times and other publications proved, it was understood by anyone who took time to read Silent Spring that Carson was not an absolutist seeking to stop all pesticide use.

DDT had been effective against malaria in Europe, in Northern Africa, in parts of India and southern Asia, and even in the southern United States, where the disease was already being routed by other means. But these were mostly developed areas. Using DDT in places like sub-Saharan Africa, with its remote and hard-to-reach villages, had long been considered problematic. It was an old story and one still repeated: Africa was everybody’s lowest priority.

And in any case, the World Health Organization had begun to question its malaria-eradication program even before Silent Spring was published. One object lesson was that the heavy use of DDT in many parts of the world was producing new strains of mosquitoes resistant to the insecticide. Much as it can happen with antibiotics, the use of an environmental poison clears susceptible organisms from the ecosystem and allows those with immunity to take over. The WHO also faced declining interest in the disease among scientists and sharp reductions in funding from the international community.

When the recently created Environmental Protection Agency banned DDT for most domestic uses in 1972, this ruling had no force in other parts of the world and the insecticide remained part of the international anti-malaria arsenal. The United States continued to manufacture and export DDT until the mid-1980s, and it has always been available from pesticide makers in other countries.

One result is that DDT is still with us—globally adrift in the atmosphere from spraying operations in various parts of the world, and also from its continuing volatilization from soils in which it has lain dormant for decades. The threat of DDT to wildlife—as a deadly neurotoxin in many species and a destroyer of reproductive capabilities in others—has never been in doubt. Carson’s claims in Silent Spring about DDT’s connection to human cancer and other disorders have not been completely resolved. The National Toxicology Program lists DDT as “reasonably anticipated to be a human carcinogen.” The same holds for two of its common break-down products, DDD and DDE, which are also suspected of causing developmental problems in humans.

These are cloudy but worrisome presumptions. DDT is stored in fat tissues—including ours—and that storage amplifies with repeated exposures over time, as well as through food chains, with unpredictable consequences. We walk around with our personal body-burden of DDT, a poison we still consume both from its decades-old residuals and its ongoing uses. If Rachel Carson hoped to end the use of DDT and our exposure to it, she did a lousy job.

In 2006, the World Health Organization announced a renewed commitment to fighting malaria with DDT, mainly in Africa—where the WHO had never lifted its approval for this purpose. The move was backed by environmental groups, as it surely would have been by Rachel Carson had she been with us still.

William Souder’s On a Farther Shore: The Life and Legacy of Rachel Carson, is out as of Sept. 4.