Sagan's most important contributions in his final years were in the struggle against pseudoscience. Throughout the last decade of the millennium, this scourge of public irrationality grew, as astrology, alien abductions, alternative medicine, and any number of other New Age and "millennial" fads and cults gained in popularity. Sagan fought back, and after the death of his friend Isaac Asimov, his was the voice most often heard in defense of scientific reason in the United States.

His most influential platform was provided by the weekly newspaper-supplement magazine Parade, one of the two most widely read publications in America. His column appeared there regularly for more than a decade, providing a unique opportunity for outreach and education. He discussed the latest discoveries in science, debunked the purveyors of flimflam, and also delved into sensitive topics of public concern such as abortion and animal rights. His articles in Parade provided the basis for many chapters in his final three books, Pale Blue Dot, The Demon-Haunted World; and Billions and Billions.

The Demon-Haunted World, subtitled Science as a Candle in the Dark, was a passionate defense of science against pseudoscience and irrationality, as illustrated in the following quotes. "It is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring [that may be]….Superstition and pseudoscience keep getting in the way [of understanding nature], providing easy answers, dodging skeptical scrutiny, casually pressing our awe buttons and cheapening the experience, making us routine and comfortable practitioners as well as victims of credulity…. [Pseudoscience] ripples with gullibility…. The tenants of skepticism do not require an advanced degree to master, as most successful used car buyers demonstrate. The whole idea of democratic application of skepticism is that everyone should have the essential tools to effectively and constructively evaluate claims to knowledge…. But the tools of skepticism are generally unavailable to the citizens of our society…. Those who have something to sell, those who wish to influence public opinion, those in power, a skeptic might suggest, have a vested interest in discouraging skepticism" (Sagan 1995).

While vigorously advocating the concepts of scientific skepticism, Sagan also raised questions about strategy. He wrote that "The chief difficulty I see in the skeptical movement is in its polarization: Us vs. Them—the sense that we [skeptics] have a monopoly on the truth; that those other people who believe all these stupid doctrines are morons." He was especially troubled by anti-religious attitudes. While not a believer himself, Sagan had constructive interactions with religious leaders, including the Pope and the Dalai Lama. He wrote "There is no necessary conflict between science and religion. On one level, they share similar and consonant goals, and each needs the other."

Although more demanding and hence less popular than his books about astronomy and planetary exploration, The Demon-Haunted World is arguably his most mature and valuable publication. Expressing his concerns about the irrationalism that pervades modern society, he wrote: "I know that the consequences of scientific illiteracy are far more dangerous in our time than in any time that has come before. It's perilous and foolhardy for the average citizen to remain ignorant about global warming, say, or ozone depletion, air pollution, toxic and radioactive wastes, topsoil erosion, tropical deforestation, exponential population growth…. How can we affect national policy—or even make intelligent decisions in our own lives—if we don't grasp the underlying issues?... Plainly there is no way back. Like it or not, we are stuck with science. We had better make the best of it. When we finally come to terms with it and fully recognize its beauty and power, we will find, in spiritual as well as in practical matters, that we have made a bargain strongly in our favor."

Sagan's example has contributed to increasing efforts by scientists to reach out to the press and the public. For the first time in the 1980s, such professional organizations as the American Astronomical Society and the American Geophysical Union appointed full-time press officers and began sponsoring press conferences at their annual meetings. NASA missions also undertook to identify and encourage project scientists to speak with the press, both informally and as official NASA spokespersons. In the late 1990s this extended to welcoming commercial HDTV crews into high-level NASA meetings and spacecraft encounters. Breaking with tradition, the space agency was now anxious to show the human side of scientific exploration. In the 1960s, Sagan was almost alone in his work with the press, but such activity had become relatively common among space scientists two decades later. None, however, has approached Sagan's level of charisma or public name recognition.

Cornell's President Frank Rhodes, speaking at Sagan's sixtieth birthday celebration, summarized his impact: "I want to salute Carl Sagan…as the embodiment of everything that is best in academic life… in scholarship, teaching, and service….Carl is an inspiring example of the engaged, global citizen…. [He is] a master of synthesis, and he has used that skill to engage us as a society in some of the biggest issues of our time…. With the conscience of a humanist and the consummate skill of the scientist, he addresses the needs of the society in which we live, and we are the richer for it" (Terzian and Bilson 1997.)

The above is an excerpt taken for David Morrisons Carl Sagan's Life and Legacy as Scientist, Teacher, and Skeptic which was published in the January/February 2007 issue of Skeptical Inquirer magazine.