The world lost an outstanding scientist and teacher and one of the foremost public intellectuals of our time when Stephen Jay Gould died of cancer on May 20 at the age of 60.

Gould’s accomplishments as a scientist spanned several fields. He made significant contributions to the development of the theory of evolution, the science of paleontology (study of fossils), and the history of science. His fresh and often provocative insights as well as his critical spirit helped to promote and encourage an atmosphere of healthy intellectual ferment and wrangling over a number of important scientific issues. His influence reached far beyond Harvard University, where he taught for three decades, or the world of professional scientists. He made crucial contributions in the fight against the right-wing religious fundamentalists and their organized campaigns aimed at discrediting the science of evolution and preventing people from learning about it.Gould staunchly defended the well-established facts of evolution and the basic principles of the theory of evolution. This theory explains that all life forms are the products of billions of years of evolution—from single-celled bacteria to the most advanced animals, including human beings—and that all species have descended from other species and share common ancestors. At the same time, Gould contributed to further extending and developing this important field of science.As a foe of anti-scientific religious creationism, he rushed to Kansas in 1999 to oppose the banning of the teaching of evolution by the state board of education. "To teach biology without evolution is like teaching English without grammar," he said.Gould also sharply exposed the corrupt and reactionary social policies as well as the fundamentally flawed science of those who have tried to spread lies and distortions to promote reactionary and racist views. He was a scientific opponent of genetic determinism—the attempt to reduce all human activity to the operation of our genes.

Gould had no patience for those who claimed to be "scientific" and "objective"—and then used faulty or dishonest pseudoscience to promote views that upheld social injustice. His book The Mismeasure of Man was a powerful refutation of such misuse of science. And in it he took apart the arguments of those who promoted biodeterminism—the idea that complex individual behavior and social and cultural phenomena are determined by biological factors—and who use this theory to justify inequality in society.The book was originally published in 1981, as an answer to Arthur Jensen and others who claimed that there were innate and largely unchangeable differences in intelligence between groups, in particular between white and Black people. A revised and expanded edition was published in 1996, at a time when there was a renewed offensive by those pushing biodeterminist arguments about human intelligence and abilities, such as The Bell Curve by Richard Herrnstein and Charles Murray.

In 1971, as a young professor at Harvard, Gould and his colleague Niles Eldredge published a landmark article on "speciation and punctuated equilibria." While placing themselves firmly within the tradition of Charles Darwin, the founder of the science of evolution, Gould and Eldredge proposed a modification of Darwin’s view on the pace of evolutionary change and the development of new species. Darwin maintained that biological evolution developed slowly and gradually. Gould and Eldredge reexamined fossil data and came up with a new interpretation: evolution proceeds through long periods of relatively little change in species interrupted by short periods (in geological time) of relatively rapid change, "punctuated equilibrium."

Over the next 30 years, Gould made many other important contributions to the development of evolutionary biology. Evolution is considered to be one of the best established facts in all of science. The proof and evidence are abundant. But like any scientific theory, Darwinism has had to be further developed in light of new discoveries and understanding.Darwin could not have anticipated the full variety and complexity of issues that have arisen in evolutionary biology during the 120 years since his death.

Gould was a skillful and influential popularizer of science. Effectively combining science and art, he wrote many entertaining essays and books that spread the understanding of important scientific facts, principles, and methods among a broad public. One of Gould’s trademarks was illustrating and explaining scientific principles by drawing on a wide range of subject matter, from literature and architecture to popular movies and one of his lifelong passions, baseball. His infectious enthusiasm for his subject matter, his encyclopedic knowledge, and his engaging writing style drew an ever-expanding audience. Richard Lewontin, one of Gould’s closest friends and colleagues, said, "He was the best science writer for the public when it came to explaining evolution. Steve did not try to make it simple, he tried and succeeded in explaining the complications. He made readers appreciate how messy and variable life is.... Steve always told the truth in ways people could understand, and he did it better than anyone." For 27 years, Gould wrote an article every month for Natural History magazine; his 300th and final essay for the magazine was published in the January 2001 issue.