Broca's Brain

by Carl Sagan

In the history of the world there have been, probably, tens of thousands of different religions. There is a well-intentioned pious belief that they are all fundamentally identical. In terms of an underlying psychological resonance, there may indeed be important similarities at the cores of many religions, but in the details of ritual and doctrine, and the apologias considered to be authenticating, the diversity of organized religions is striking. Human religions are mutually exclusive on such fundamental issues as one god versus many; the origin of evil; reincarnation; idolatry; magic and witchcraft; the role of women; dietary proscriptions; rites of passage; ritual sacrifice; direct or mediated access to deities; slavery; intolerance of other religions; and the community of beings to whom special ethical considerations are due. We do no service to religion in general or to any doctrine in particular if we paper over these differences. Instead, I believe we should understand the world views from which differing religions derive and seek to understand what human needs are fulfilled by those differences.

  Bertrand Russell once told of being arrested because he peacefully protested Britain’s entry into World War I. The jailer asked—then a routine question for new arrivals—Russell’s religion. Russell replied, “Agnostic,” which he was asked to spell. The jailer smiled benignly, shook his head and said, “There’s many different religions, but I suppose we all worship the same God.” Russell commented that the remark cheered him for weeks. And there may not have been much else to cheer him in that prison, although he did manage to write the entire Introduction to Mathematical Philosophy and started reading for his work The Analysis of Mind within its confines.

  Many of the people who ask whether I believe in God are requesting reassurance that their particular belief system, whatever it is, is consistent with modern scientific knowledge. Religion has been scarred in its confrontation with science, and many people—but by no means all—are reluctant to accept a body of theological belief that is too obviously in conflict with what else we know. Apollo 8 accomplished the first manned lunar circumnavigation. In a more or less spontaneous gesture, the Apollo 8 astronauts read from the first verse of the Book of Genesis, in part, I believe, to reassure the taxpayers back in the United States that there were no real inconsistencies between conventional religious outlooks and a manned flight to the Moon. Orthodox Muslims, on the other hand, were outraged after Apollo 11 astronauts accomplished the first manned lunar landing, because the Moon has a special and sacred significance in Islam. In a different religious context, after Yuri Gagarin’s first orbital flight, Nikita Khrushchev, the chairman of the Council of Ministers of the USSR, noted that Gagarin had stumbled on no gods or angels up there—that is, Khrushchev reassured his audience that manned orbital flight was not inconsistent with its beliefs.

  In the 1950s a Soviet technical journal called Voprosy Filosofü (Problems in Philosophy) published an article that argued—very unconvincingly, it seemed to me—that dialectical materialism required there to be life on every planet. Some time later an agonized official rebuttal appeared, decoupling dialectical materialism from exobiology. A clear prediction in an area undergoing vigorous study permits doctrines to be subject to disproof. The last posture a bureaucratic religion wishes to find itself in is vulnerability to disproof, where an experiment can be performed on which the religion stands or falls. And so the fact that life has not been found on the Moon has left the foundations of dialectical materialism unshaken. Doctrines that make no predictions are less compelling than those which make correct predictions; they are in turn more successful than doctrines that make false predictions.

  But not always. One prominent American religion confidently predicted that the world would end in 1914. Well, 1914 has come and gone, and—while the events of that year were certainly of some importance—the world does not, at least so far as I can see, seem to have ended. There are at least three responses that an organized religion can make in the face of such a failed and fundamental prophecy. They could have said, “Oh, did we say ‘1914’? So sorry, we meant ‘2014.’ A slight error in calculation. Hope you weren’t inconvenienced in any way.” But they did not. They could have said, “Well the world would have ended, except we prayed very hard and interceded with God so He spared the Earth.” But they did not. Instead, they did something much more ingenious. They announced that the world had in fact ended in 1914, and if the rest of us hadn’t noticed, that was our lookout. It is astonishing in the face of such transparent evasions that this religion has any adherents at all. But religions are tough. Either they make no contentions which are subject to disproof or they quickly redesign doctrine after disproof. The fact that religions can be so shamelessly dishonest, so contemptuous of the intelligence of their adherents, and still flourish does not speak very well for the tough-mindedness of the believers. But it does indicate, if a demonstration were needed, that near the core of the religious experience is something remarkably resistant to rational inquiry.

  Andrew Dickson White was the intellectual guiding light, founder and first president of Cornell University. He was also the author of an extraordinary book called The Warfare of Science with Theology in Christendom, considered so scandalous at the time it was published that his co-author requested his name omitted. White was a man of substantial religious feeling.* But he outlined the long and painful history of erroneous claims which religions had made about the nature of the world, and how, when people directly investigated the nature of the world and discovered it to be different from doctrinal contentions, such people were persecuted and their ideas suppressed. The aged Galileo was threatened by the Catholic hierarchy with torture because he proclaimed the Earth to move. Spinoza was excommunicated by the Jewish hierarchy, and there is hardly an organized religion with a firm body of doctrine which has not at one time or another persecuted people for the crime of open inquiry. Cornell’s own devotion to free and non-sectarian inquiry was considered so objectionable in the last quarter of the nineteenth century that ministers advised high school graduates that it was better to receive no college education than to attend so impious an institution. Indeed, this Sage Chapel was constructed in part to placate the pious—although, I am glad to say, it has from time to time made serious efforts at open-minded ecumenicism.

  Many of the controversies which White describes are about origins. It used to be believed that every event in the world—the opening of a morning glory, let us say—was due to direct microintervention by the Deity. The flower was unable to open by itself. God had to say, “Hey, flower, open.” The application of this idea to human affairs has often had desultory social consequences. For one thing it seems to imply that we are not responsible for our actions. If the play of the world is produced and directed by an omnipotent and omniscient God, does it not follow that every evil that is perpetrated is God’s doing? I know this idea is an embarrassment in the West, and attempts to avoid it include the contention that what seems to be evil is really part of the Divine Plan, too complex for us to fathom; or that God chose to cloud his own vision about the causality skein when he set out to make the world. There is nothing utterly impossible about these philosophical rescue attempts, but they do seem to have very much the character of propping up a teetering ontological structure.* In addition, the idea of microintervention in the affairs of the world has been used to support the established social, political and economic conventions. There was, for example, the idea of a “Divine Right of Kings,” seriously argued by philosophers such as Thomas Hobbes. If you had revolutionary thoughts directed, let us say, toward George III, you were guilty of blasphemy and impiety, religious crimes, as well as such more commonplace political crimes as treason.

  There are many legitimate scientific issues relating to origins and ends: What is the origin of the human species? Where did plants and animals come from? How did life arise? the Earth, the planets, the Sun, the stars? Does the universe have an origin, and if so, what? And finally, a still more fundamental and exotic question, which many scientists would say is essent
ially untestable and therefore meaningless: Why are the laws of nature the way they are? The idea that a God or gods is necessary to effect one or more of these origins has been under repeated attack over the last few thousand years. Because we know something about phototropism and plant hormones, we can understand the opening of the morning glory independent of divine microintervention. It is the same for the entire skein of causality back to the origin of the universe. As we learn more and more about the universe, there seems less and less for God to do. Aristotle’s view was of God as an unmoved prime mover, a roi fainéant, a do-nothing king who establishes the universe in the first place and then sits back and watches the intricate, intertwined chains of causality course down through the ages. But this seems abstract and removed from everyday experience. It is a little unsettling and pricks at human conceits.

  Humans seem to have a natural abhorrence of an infinite regression of causes, and this distaste is at the root of the most famous and most effective demonstrations of the existence of God by Aristotle and Thomas Aquinas. But these thinkers lived before the infinite series was a mathematical commonplace. If the differential and integral calculus or transfinite arithmetic had been invented in Greece in the fifth century B.C., and not subsequently suppressed, the history of religion in the West might have been very different—or at any rate we would have seen less of the pretension that theological doctrine can be convincingly demonstrated by rational argument to those who reject alleged divine revelation, as Aquinas attempted in the Summa Contra Gentiles.

  When Newton explained the motion of the planets by the universal theory of gravitation, it no longer was necessary for angels to push and pummel the planets about. When Pierre Simon, the Marquis de Laplace, proposed to explain the origin of the solar system—although not the origin of matter—in terms of physical laws as well, even the necessity for a god involved in the origins of things seemed profoundly challenged. Laplace is said to have presented an edition of his seminal mathematical work Mécanique céleste to Napoleon aboard ship in the Mediterranean during the Napoleonic expedition to Egypt, 1798 to 1799. A few days later, so the story goes, Napoleon complained to Laplace that he had found no mention of God in the text.* Laplace’s response has been recorded: “Sire, I have no need of that hypothesis.” The idea of God as a hypothesis rather than as an obvious truth is by and large a modern idea in the West—although it was certainly discussed seriously and wryly by the Ionian philosophers of 2,400 years ago.

  It is often considered that at least the origin of the universe requires a God—indeed, an Aristotelian idea.† This is a point worth looking at in a little more detail. First of all, it is perfectly possible that the universe is infinitely old and therefore requires no Creator. This is consistent with existing knowledge of cosmology, which permits an oscillating universe in which the events since the Big Bang are merely the latest incarnation in an infinite series of creations and destructions of the universe. But secondly, let us consider the idea of a universe created somehow from nothing by God. The question naturally arises—and many ten-year-olds spontaneously think of it before being discouraged by their elders—where does God come from? If we answer that God is infinitely old or present simultaneously in all epochs, we have solved nothing, except perhaps verbally. We have merely postponed by one step coming to grips with the problem. A universe that is infinitely old and a God that is infinitely old are, I think, equally deep mysteries. It is not readily apparent why one should be considered more reliably established than the other. Spinoza might have said that the two possibilities are not really different ideas at all.

  I think it is wise, when coming face to face with such profound mysteries, to feel a little humility. The idea that scientists or theologians, with our present still puny understanding of this vast and awesome cosmos, can comprehend the origins of the universe is only a little less silly than the idea that Mesopotamian astronomers of 3,000 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. We simply do not know. The Hindu holy book, the Rig Veda (X:129), has a much more realistic view of the matter:

  Who knows for certain? Who shall here declare it?

  Whence was it born, whence came creation?

  The gods are later than this world’s formation;

  Who then can know the origins of the world?

  None knows whence creation arose;

  And whether he has or has not made it;

  He who surveys it from the lofty skies,

  Only he knows—or pernaps he knows not.

  But the times we live in are very interesting ones. Questions of origins, including some questions relating to the origin of the universe, may in the next few decades be amenable to experimental inquiry. There is no conceivable answer to the grand cosmological questions which will not resonate with the religious sensibilities of human beings. But there is a chance that the answers will discomfit a great many bureaucratic and doctrinal religions. The idea of religion as a body of belief, immune to criticism, fixed forever by some founder is, I think, a prescription for the long-term decay of the religion, especially lately. In questions of origins and ends, the religious and the scientific sensibilities have much the same objectives. Human beings are built in such a way that we passionately wish to answer these questions—perhaps because of the mystery of our own individual origins. But our contemporary scientific insights, while limited, are much deeper than those of our Babylonian predecessors of 1,000 B.C. Religions unwilling to accommodate to change, both scientific and social, are, I believe, doomed. A body of belief cannot be alive and relevant, vibrant and growing, unless it is responsive to the most serious criticism that can be mustered against it.

  The First Amendment to the United States Constitution encourages a diversity of religions but does not prohibit criticism of religion. In fact it protects and encourages criticism of religion. Religions ought to be subject to at least the same degree of skepticism as, for example, contentions about UFO visitations or Velikovskian catastrophism. I think it is healthy for the religions themselves to foster skepticism about the fundamental underpinnings of their evidential bases. There is no question that religion provides a solace and support, a bulwark in time of emotional need, and can serve extremely useful social roles. But it by no means follows that religion should be immune from testing, from critical scrutiny, from skepticism. It is striking how little skeptical discussion of religion there is in the nation that Tom Paine, the author of The Age of Reason, helped to found. I hold that belief systems that cannot survive scrutiny are probably not worth having. Those that do survive scrutiny probably have at least important kernels of truth within them.

  Religion used to provide a generally accepted understanding of our place in the universe. That surely has been one of the major objectives of myth and legend, philosophy and religion, as long as there have been human beings. But the mutual confrontation of differing religions and of religion with science has eroded those traditional views, at least in the minds of many.* The way to find out about our place in the universe is by examining the universe and by examining ourselves—without preconceptions, with as unbiased a mind as we can muster. We cannot begin with an entirely clean slate, since we arrive at this problem with predispositions of hereditary and environmental origin; but, after understanding such built-in biases, is it not possible to pry insights from nature?

  Proponents of doctrinal religions—ones in which a particular body of belief is prized and infidels scorned—will be threatened by the courageous pursuit of knowledge. We hear from such people that it may be dangerous to probe too deeply. Many people have inherited their religion like their eye color: they consider it not a thing to think very deeply about, and in any case beyond our control. But those with a set of beliefs they profess to feel deeply about, which they have selected without an unbiased sifting through the facts and the alternatives, will feel uncomfortably cha
llenged by searching questions. Anger at queries about our beliefs is the body’s warning signal: here lies unexamined and probably dangerous doctrinal baggage.

  Christianus Huygens wrote a remarkable book around 1670 in which bold and prescient speculations were made about the nature of the other planets in the solar system. Huygens was well aware that there were those who held such speculations and his astronomical observations objectionable: “But perhaps they’ll say,” Huygens mused, “it does not become us to be so curious and inquisitive in these Things which the Supreme Creator seems to have kept for his own Knowledge: For since he has not been pleased to make any farther Discovery or Revelation of them, it seems little better than presumption to make any inquiry into that which he has thought fit to hide. But these Gentlemen must be told,” Huygens then thundered, “that they take too much upon themselves when they pretend to appoint how far and no farther Men shall go in their Searches, and to set bounds to other Mens Industry; as if they knew the Marks that God has placed to Knowledge: or as if Men were able to pass those Marks. If our Forefathers had been at this rate scrupulous, we might have been ignorant still of the Magnitude and Figure of the Earth, or that there was such a place as America.”

  If we look at the universe in the large, we find something astonishing. First of all, we find a universe that is exceptionally beautiful, intricately and subtly constructed. Whether our appreciation of the universe is because we are a part of that universe—whether, no matter how the universe were put together, we would have found it beautiful—is a proposition to which I do not pretend to have an answer. But there is no question that the elegance of the universe is one of its most remarkable properties. At the same time, there is no question that there are cataclysms and catastrophes occurring regularly in the universe and on the most awesome scale. There are, for example, quasar explosions which probably decimate the nuclei of galaxies. It seems likely that every time a quasar explodes, more than a million worlds are obliterated and countless forms of life, some of them intelligent, are utterly destroyed. This is not the traditional benign universe of conventional religiosity in the West, constructed for the benefit of living and especially of human beings. Indeed, the very scale of the universe—more than a hundred billion galaxies, each containing more than a hundred billion stars—speaks to us of the inconsequentiality of human events in the cosmic context. We see a universe simultaneously very beautiful and very violent. We see a universe that does not exclude a traditional Western or Eastern god, but that does not require one either.