Carl Sagan and Modern Scientific Humanism1

This is actually the thirteenth in a series of articles written by Pat Duffy Hutcheon on the evolution of humanist thought. However, it was published out of order because of Dr. Sagan's untimely death (in late 1996) in Humanist in Canada (Autumn 1997), p.6-9; 33.

KEY TERMS: pseudoscience -- anti-science -- mysticism -- scientific method -- postmodernism -- scientific illiteracy -- agnosticism -- spirituality

Carl Sagan was one of the greatest humanists who ever lived, although he seldom, if ever, used the term. He devoted his life to educating the public about science -- and to educating scientists about their responsibility for how scientific knowledge is used -- in an age when both were considered by the academic community to be inappropriate pursuits. He fought a long-term battle against the pseudoscience and anti-science that are spreading like a rot in modern culture. And, through his success in organizing physicists to communicate the message about the nature of the nuclear winter that would predictably result from the deployment of hydrogen bombs, Carl Sagan, more than any other one person, may have been responsible for the avoidance of nuclear war in our lifetime.

Carl was born in 1934, the only son of Jewish immigrants from Russia. His father was a cutter in a New York garment factory. His sister and only sibling says that, as a child "he was always reaching for the stars" -- and always entranced by the possibility that there might be some form of life elsewhere. His first summer job was in the lab of a leading astronomer who was working on the subject of the origin of life on earth. He studied astronomy and astro-physics at the University of Chicago. His PhD dissertation was unique in that it amounted to a significant scientific breakthrough. He had gathered evidence for the thesis that something had occurred on Venus to produce a devastating Greenhouse Effect, from which the planet had never recovered.

If ever anyone was in the right place at the right time, and with the right credentials, it was Carl Sagan when he graduated in 1957 -- the year the Russians launched SPUTNIK. He was immediately invited to join the first planetary expedition of the newly formed NASA expedition to Venus (the 1962 Mariner II). He was thus in a position to witness, firsthand, the confirmation of his own doctoral thesis. This made his reputation as a scientist at the very moment in history when US space research was getting off the ground.

In 1963 Sagan was hired by Harvard to teach astronomy. While there he was involved with Mariner IV, NASA's first probe to Mars. The news of an environment apparently hostile to life was a crushing disappointment to him. At the same time, he was finding himself increasingly lonely at Harvard, and Harvard was becoming increasingly unhappy with him. They were not comfortable with an astronomer and physicist who wanted to educate the ordinary person about science, and to educate scientists about their unique responsibility for the future of life and human culture. In 1968 he was passed over for tenure. While this is usually the kiss of death for a young academic, Sagan was immediately snapped up by Cornell University. He became the Director of their new Laboratory for Planetary Sciences, and remained in that capacity until his death in December of 1996.

Meanwhile, in 1969, when NASA put Apollo II on the moon, Sagan was one of the experts responsible for briefing the astronauts. The subsequent "pioneer missions" to space included a Galactic Greeting which he had designed. He was by then campaigning for another mission to Mars -- one that would actually land there. Viking II was sent in 1976. It became the first man-made object to send pictures of the Martian landscape back to earth. The pictures revealed a surprisingly familiar-looking rocky desert with no evidence of life.

In 1977 Carl Sagan became a media star with the publication of his popular book, The Dragons of Eden. That same year he and Annie Druyen, who was to be his third wife, produced a disk to be taken into space. It was called Sounds of Planet Earth. Sagan referred to it as "a message in a bottle thrown into the future". Also that same year, he and Annie began planning a thirteen-part television series named Cosmos: a project that lasted three years and required filming in twelve different countries. It was aired in 1980. That same year The Voyager spacecraft sent back the first pictures of Jupiter and Saturn. In 1981 the launch of the shuttle Columbia marked the end of NASA's program of large-scale space travel. In 1982 the American Congress allocated funds to support a long-sought official search for extra-terrestrial intelligence. During this period Sagan suffered a severe, life-threatening illness. For these, and a number of additional reasons, he began to focus all of his remarkable talents and energies on the prospects for continuing life here on our seemingly unique and fragile Earth.

Near the end of his life Sagan told of being asked by a student, "Now that you have successfully debunked everything that we have been taught to believe about the human role and origin in the Universe, what is there left for us?" His answer for the student, and for all human beings, was "Do something worthwhile with this amazing life while you have it!"

Did Carl Sagan in fact merely tear down old beliefs without putting anything better in their place? Far from it! Even for those who never met him, he left behind a treasure trove of published works which put the lie to that accusation. His life was dedicated, not to tearing down, but to building a positive, integrated world view capable of providing better guidance for human beings in the centuries to come than our ancient inherited mythologies could ever do.

He was worried about the welfare of a humankind that was being forced to navigate the perilous waters of the future with one foot aboard the seaworthy craft of science and the other embedded in the quicksand of mysticism along the shore. "We compartmentalize", he said, referring even to the highly schooled among us. "Some scientists do this too, effortlessly stepping between the skeptical world of science and the credulous world of religious belief without missing a beat....But we cannot have science in bits and pieces, applying it where we feel safe and ignoring it where we feel threatened."2 He explained that science is a way of thinking much more than it is a body of knowledge. It provides an integrated, yet evolving and open-ended, frame of reference for making sense out of experience -- all experience. The goal of science is to discover how the world works, to look for regularities, to understand the connections of things. It is an all-encompassing approach that is rooted in childhood trial-and-error forays into our surroundings, and the learnings that result from the consequences of such everyday "experiments" in living. And it develops from there, with no discrete break, into the formal public endeavor requiring open and precise communication of research plans and methods as well as a collective process of checking up on results. Sagan admitted that the results of scientific inquiry can never be the "Truths" or "the essence of reality" claimed by mystics and purportedly embodied in the mythologies of most religions. This means that they cannot offer us the illusion of certainty that so many religious natures seem to crave. But they are by far the best that fallible humans can hope for. Sagan quoted Einstein's famous comment that, "All of our science, measured against reality, is primitive and childlike -- and yet it is the most precious thing we have.3 He warned that there are already many signs that American culture may be on the verge of forsaking science for mysticism, and thereby sliding back almost without noticing it into superstition and the darkness that engulfed our demon-haunted world for thirteen centuries after the fall of Rome.

Sagan explained that, at the heart of science, there are two distinguishing features which make it uniquely valuable as the foundation of a workable world view. One of these is the self-correcting mechanism that not only allows for, but encourages, an unrelenting process of testing propositions in terms of their workability and falsifiability. The other is an essential balance between two attitudes: "an openness to new ideas, no matter how counter-intuitive, and the most ruthlessly skeptical scrutiny of all ideas, old and new."4

Sagan had good reason to be concerned about the attacks that have been mounted against science in recent years. Many of these have come from the literary and philosophical movement referred to loosely as "postmodernism". Proponents of the scientific world view have been accused by the postmodernists of "idolizing" science; and of belonging to a secret, elite society seeking to maintain a monopoly on specialized knowledge which is no different in its essence from the truth claims of New Age mysticism. It has even been claimed that scientists are arrogant power mongers who negotiate and/or impose their theories on the rest of us; that they are as prejudiced as anyone else; and that throughout history their theories have been merely reflections of their own class and gender biases with no more dependability than "any other form of ideology." As a group, scientists have been called nerdy "left-brainers" -- arrogant, destroyers of the awe and wonder of nature, and architects of the "disenchantment" of humanity. They are said to be obsessed with imposing an artificial order on nature for the satisfaction of their own needs when, "in fact, the new physics has demonstrated that reality is random and chaotic and, in its very essence, 'unknowable"

Unlike most scientists who prefer to remain above the fray, Sagan felt that he had a responsibility to the future to respond to such charges. As to the first of the above, he said, the scientific method of inquiry is "far from being idolatry. [It is, instead,] the means by which we can distinguish the false idols from the real thing."5 And as for science being secretive, Sagan maintained that it is the most publicly communicated and objectively tested endeavor in all of human culture. In response to the common criticism that quantum mechanics is no less mysterious than shamanistic or theological or New Age beliefs, he said that, even if we cannot understand it, we can verify that quantum mechanics works; in fact, we don't have to understand a scientific theory fully in order to observe what it predicts. It is the unreliability of the predictions of mystical doctrines that marks them as useless.

He explained as well that "scientists do not seek to impose their needs and wants on Nature, but instead humbly interrogate Nature and take seriously what they find."6 In fact scientific theories, by their very nature, cannot be negotiated or politically imposed. The process of interrogating Nature is necessarily a two-way enterprise, with Nature fighting back in no uncertain terms if the questioner gets out of line. Theories from which refutable hypotheses cannot be derived are not scientific. Those that imply testable propositions which are subsequently refuted are discarded. It is this periodic discarding of theories which are no longer fruitful that is the source of the revolutions in science which so many people fail to understand. The "facts" or rules revealed by scientific inquiry have not altered -- only the theory explaining and guiding the process has been replaced, with the older one remaining in use in those circumstances where it continues to "work." Sagan concluded that it is this rapid rate of change in science in recent times that is responsible for some of the fire it draws, and for the accusation that it is merely one among a number of contending ideologies.

Many social scientists are guilty of pandering to anti-science thinking, according to Sagan. They want to have it both ways: to have the respect traditionally granted to science in the public domain without being burdened by its methods and rules. They seem not to understand, he said, that the credibility of science is a consequence of its method -- the very thing that they either fail to comprehend or stubbornly refuse to follow. Bad science inevitably drives out good. He also deplored the way that popular tabloids contribute to a confusion of pseudoscence with science by their concerted attempt to make science (the very instrument of skeptical inquiry) appear to confirm ancient faiths and popular occult propositions, all of which are devised in such a way that they are neither subject to disconfirmation nor amenable to rational discussion. The latter are limbic, right-hemisphere-inspired doctrines, Sagan said. Although natural human responses to the complexity of our surroundings, they are fatally limited if not subject to the intervention of the fully functioning neocortex -- a left-hemispheric reason that works over the world's inputs as they are actually experienced.

The charge that individual scientists are no more objective than anyone else -- and fully as prone to pursuing their own self-interests -- has nothing to do with the reliability of science in general, according to Sagan. It is the previously described formal process of inquiry that distinguishes science from pseudoscience -- not the value neutrality of its practitioners. Science thrives on errors, he said, correcting or discarding them one by one. Pseudoscience does the opposite, framing propositions precisely so that they are invulnerable to falsifiability. Incredibly, the onus is then placed on doubters to disprove them! However, Sagan recognized that the relative success of pseudoscience today rests upon something else as well -- on an alarming upsurge of credulity within the population. "Our politics, advertising and religions (New Age and Old) are awash in credulity. 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."7 Without scientific habits of thought, he said, "we risk becoming a ... world of suckers, up for grabs by the next charlatan who saunters along. [Precious television time is devoted to teaching our children] murder, rape, cruelty, superstition, credulity and consumerism ... What kind of society could we create if, instead, we drummed into them science and a sense of hope?"8

As for the popular claim that science destroys our sense of wonder and has contributed to the "disenchantment" of humanity, Sagan would have none of it. He reminded us that any protozoology or bacteriology textbook is filled with wonders that far outshine those derived from the hallucinatory imaginings of mystics and pseudo scientists. And why, he asked, is a sense of enchantment founded on ignorance considered more desirable than the self-knowledge available through authentic science? "If we long to believe that the stars rise and set for us, that we are the reason there is a Universe, does science do us a disservice by deflating our conceits?9

Sagan also pointed out numerous times that "the order of the Universe is not an assumption; it is an observed fact."10 And that the simplest definition of science is the search for rules -- which is, in turn, the only possible way to understand our vast and complex Universe. Sagan admitted that "human beings are, understandably, highly motivated to find regularities, natural laws.... The Universe forces those who live in it to understand it. Those creatures who find everyday experience a muddled jumble of events with no predictability, no regularity, are in grave peril. The Universe belongs to those who, at least to some degree, have figured it out."11 As for it being "unknowable", he commented as follows: "For myself, I like a Universe that includes much that is unknown and, at the same time, much that is knowable. A universe in which everything is known would be static and dull, as boring as the heaven of some weak-minded theologians. A Universe that is unknowable is no fit place for thinking beings. The ideal Universe for us is very much like the one we inhabit. And I guess that is really not much of a coincidence".12

More than anything, Sagan feared the consequences of scientific illiteracy in the public at large. "When governments and societies lose the capacity for critical thinking, the results can be catastrophic -- however sympathetic we may be for those who have bought the baloney."13 Elsewhere he quoted an egregious example of what can happen when elite opinion-shapers connive to encourage general gullibility: "A new era of the magical explanation of the world is rising, an explanation based on will rather than knowledge. There is no truth in either the moral or the scientific sense."14 The speaker of these words was Adolph Hitler, but the sentiments had been encouraged for at least a century by the intellectual ancestors of today's "postmodernist" philosophers.

Humanists will be interested in what Carl Sagan had to say about religion. In one of his earliest books he spelled out the basis of his scientific agnosticism, as applied to religious belief. "Those who raise questions about the God hypothesis and the soul hypothesis are by no means all atheists. An atheist is someone who is certain that God does not exist, someone who has compelling evidence against the existence of God. I know of no such compelling evidence... Considering the enormous emotional energies with which the subject is invested, a questing, courageous and open mind seems to be essential for narrowing our collective ignorance on the subject."15 He had little respect for anyone who held to dogmatic claims of any kind about the ultimate nature of reality. 'The idea that scientists or theologians, with our present and still puny understanding of this vast and awesome cosmos, can comprehend the origin of the universe is only a little less silly than the idea that the Mesopotamian astronomers of 3000 years ago -- from whom the ancient Hebrews borrowed, during the Babylonian captivity, the cosmological accounts in the first chapter of Genesis -- could have understood the origins of the universe.15

He did not attack traditional religions, but he did chide them for having made a fatal mistake in continuing to assert truth claims about the nature of the cosmos and about the origins and destiny of humankind: claims that are the business of science. He thought that religion could make a positive contribution to modern society only if it forsook myth and mysticism and concentrated on activities having to do with reverence for life, awe at the wonders of nature, ethics and morality, community, the celebration of life's passages and striving for social justice.

Sagan distinguished clearly between mysticism and spirituality. While mysticism is concerned with matters of magic, the occult, the supersensual and "essentially unknowable', spirit is something quite different, he maintained. "It comes from the Latin word 'to breathe'. What we breathe is air, which is certainly matter, however thin. Despite usage to the contrary, there is no necessary implication in the word 'spirituality' that we are talking about anything other than matter (including the realm of matter of which the brain is made) or anything outside the realm of science...Science is not only compatible with spirituality; it is a profound source of spirituality...The notion that science and spirituality are somehow mutually exclusive does a profound disservice to both."16

Sagan was never unkind or arrogant when referring to religious believers. He was all too aware of the fallibility of all of us, and of the human need for re-assurance and wish-fulfillment in a frighteningly complex world. Rather than blaming and deriding the victims he cited the culture in which most people are being socialized: a culture in which the tools of skepticism are not generally being made available to children. He thought that the present situation is fraught with peril for the human race. In the end, his final message was that it is only the candles lit by the scientific method that stand between us and the gathering darkness.17


  1. This is actually the thirteenth in a series of articles written by Pat Duffy Hutcheon on the evolution of humanist thought. However, it was published out of order because of Dr. Sagan's untimely death (in late 1996) in Humanist in Canada (Autumn 1997), p.6-9; 33.
  2. Sagan, Carl. 1996. The Demon-Haunted World: Science as a Candle in the Dark. (New York: Random House) p.297.
  3. Ibid. p.2.
  4. Ibid. p.304.
  5. Ibid.p.31.
  6. Ibid. p.32.
  7. Ibid. p.77.
  8. Ibid.p.39.
  9. Ibid.p.12.
  10. Ibid. p.273.
  11. Sagan, Carl. 1974. Broca=s Brian: Reflections on the Romance of Science. (New York: Random House) p.16.
  12. Ibid. p.18.
  13. Sagan, Carl. The Demon-Haunted World. p.209.
  14. Ibid. p.261.
  15. Sagan, Carl. Broca=s Brain. p.236.
  16. Ibid.p.287.
  17. Sagan, Carl. The Demon-Haunted World. p.29-30.