22. History of Belief in Extraterrestrials

It is usually assumed that the idea of extraterrestrial aliens originated in science fiction. Most books on the history of science either foster this misconception or ignore the subject entirely. In fact, however, belief that the planets of other solar systems are inhabited was almost universal among educated people in the eighteenth and nineteenth centuries; only during the period roughly corresponding to the era between the two World Wars did scientists consider it improbable.

Very little has been written about past views of ETs. When I was researching my 1974 nonfiction book The Planet-Girded Suns, which is devoted to the subject, I got virtually all my material from primary sources of the late 17th through early 20th centuries, including magazines of those eras preserved in libraries and nonfiction books so old and neglected that they sometimes fell apart in my hands. Since then, several scholarly books have dealt with aspects of the subject, but there is still no comprehensive history. (My own book, having been issued for young people, was oversimplified and is now long out of print. In 2012 I issued an updated and expanded edition of The Planet-Girded Suns, which is suitable for both adult and high school readers and is available in paperback and as an ebook.)

Today, most of our speculations about ETs, apart from those of radio astronomers, are expressed in science fiction, although the UFO phenomenon reveals that actual belief in them is widespread. Before this century, however, such speculation was common among educated people in all fields, and though it wasn't considered myth, it had many of the characteristics of myth as we now understand them. To be sure, during that era only a small percentage of the population had education, and so it didn't constitute a widespread cultural mythology. There were no mass media then, and people who didn't read the serious books and magazines of the day probably weren't aware that other solar systems exist. But among those who knew of their existence, the conviction that they are inhabited was, till the late 19th century, virtually unanimous. In fact, when in 1854 William Whewell, a prominent scholar of the history and philosophy of science and Master of Trinity College at Cambridge, wrote a book suggesting that Earth might be unique in having intelligent inhabitants, he felt obliged to publish it anonymously because he feared such an unorthodox view would damage his reputation.

Belief in other inhabited worlds spread rapidly in the period now generally known as the Copernican Revolution. Actually, this revolution in human understanding of the universe wasn't brought about by Copernicus. Copernicus believed in the Aristotelian model of the universe wherein all the fixed stars were thought to be affixed to an outer sphere surrounding Earth; his innovation was to put the sun, rather than Earth itself, at the center of the sphere. This was of tremendous importance to the advancement of science, but it didn't alter perceptions of what the universe is like. The person who first suggested that stars are suns, those suns have planets, and their planets have inhabitants was the Italian philosopher Giordano Bruno. Bruno was burned at the stake in 1600, at least partly for this view, and his condemnation extended to his books, so that they were read only in secret. This, I suspect, had a good deal to do with the fact that believers in the new cosmology referred to themselves as Copernicans rather than Brunonians. But it didn't suppress his ideas, and by the time the century was over, everyone knowledgeable about astronomy believed in inhabited solar systems.

This belief was then known, and has been known to history, as "plurality of worlds" (a topic not considered important by historians of the early 20th century, the one period when it wasn't popular; this accounts for its subsequent obscurity). It had, of course, less impact on culture than it has today. In the first place, it was an abstract belief, a matter of principle rather than speculation about the future. It did not occur to anyone that travel between solar systems might become possible. It was assumed that mortals from one solar system could never have knowledge of the others, except perhaps in an afterlife. In the second place, although plurality of worlds was discussed by "natural philosophers"--they weren't called "scientists" until the 19th century, when Whewell coined the word--it was not expected that science could ever learn anything about the subject, nor, for that matter, offer evidence for it. The "evidence" on which belief in inhabited solar systems was based came entirely from religion.

This surprises people today. Even NASA has assumed that the idea of other inhabited worlds might upset religious fundamentalists. In the 17th through early 19th centuries, however (at least in the English-speaking countries whose literature I could examine) it was held that all planets must be inhabited because God would not make a useless world. What would the purpose of a world be, if not habitation? What would the purpose of a sun be, if not to illuminate worlds? The countless stars in the sky were considered to reveal the glory of God, but it wasn't supposed that he made them just for our enjoyment. Long sermons were preached on this subject; for example, Cotton Mather of Salem witch trial fame devoted many pages to it. An 1825 textbook for use in girls' schools stated that to reject the idea of plurality of worlds would be "to narrow our conceptions of God's character." This same logic was employed by scientists, and only the decline of belief in universal purpose led, in the late 19th century, to questioning of the belief in extraterrestrials.

As early as 1686, discussion of the topic was fashionable among ladies of high society. That was the year Bernard Fontenelle's Conversations on the Plurality of Worlds was published; it took the form of a dialogue between a countess and a Parisian philosopher with whom she was strolling through a moonlit garden, in which talk of other solar systems was interspersed with talk of love. 17th-century equivalents of feminists--who weren't accustomed to being educated in astronomy--were entranced by it, and it was translated into many languages. This book was very influencial in spreading the idea of plurality of worlds, formerly discussed only by philosophers, among the general public. Not long after, at the time of the death of Newton, vast amounts of sentimental poetry about other solar systems appeared in literary magazines, much of it by women and some based on the theme of Newton's soul viewing other solar systems on the way to heaven. People were as eager to visit them as we are today, but could imagine only one potential opportunity, a time after death when the soul "Unbounded in its ken, from prison free/Will clearly view what here we darkly see:/Those planetary worlds, and thousands more,/ Now veil'd from human sight, it shall explore." (Robert Gambol, "Beauties of the Universe," 1732.)

The first full-length scientific book about life on other planets was by Christian Huygens, inventor of the wave theory of light; it appeared in 1698, shortly after his death, in both Latin and English editions. Unlike most speculators of his era, Huygens discussed the physical as well the moral nature of ETs. "There is a sort of Animals in the World, as Oysters, Lobsters and Crab-fish, whose Flesh is on the inside of their Bones as 'twere," he wrote. "What if the Planetarians should be such? O no, some body will say, it would be a hideous sight, so ugly, that Nature has not made any but her refuse and meaner Creatures of such an odd Composition. As for that, I should not be at all moved with their ugly shape, if it were not that hereby they would be deprived of that quick and easy motion of their Hands... For 'tis a very ridiculous opinion that the common people have got among them, that it is impossible a rational Soul should dwell in any other shape than ours." This passage, written 300 years ago, is not far from what scientists are saying today.

Benjamin Franklin was a firm believer both in other worlds and in the superiority of their inhabitants to humankind. In Poor Richard's Almanac for September, 1749, he wrote, "It is the opinion of all the modern philosophers and mathematicians that the planets are habitable worlds," and in a letter to a friend he said, "Superior beings smile at our theories, and at our presumption in making them." Thomas Jefferson and John Adams both made brief references to extrasolar worlds and their inhabitants in their writings. Thomas Paine included a long description of other solar systems in Age of Reason, which, since it was addressed to the general public, spread the idea beyond the intellectual circles in which it had long been common. Unlike the majority, Paine felt that the idea of plurality of worlds was incompatible with Christianity and was therefore evidence against religion; the rebuttal this engendered, centering on the question of whether other solar systems' inhabitants had sinned and if so, had been redeemed, is typical of the controversy continuing in some circles even today.

Kant wrote extensively about other solar systems and introduced ideas about them that were extremely far-sighted for his time--but the topic was considered so insignificant early in this century that most of this discussion was omitted when his book Universal Natural History and Theory of the Heavens was translated into English. The two major relevant concepts he introduced were the idea that not all planets are inhabited even if some are, and the possibility "that celestial bodies which are not yet inhabited will be hereafter, when their development has reached a late stage." These ideas were far too advanced to gain acceptance, and they had little influence on the views of his 18th-century contemporaries.

The real debate about plurality of worlds began with Whewell, mentioned above, and was extremely heated in British and American papers and magazines of the 1850s. Most of the heat was directed against Whewell, whose identity soon became known despite the fact that his name didn't appear on his book. "We scarcely expected," said the London Daily News, "that in the middle of the nineteenth century a serious attempt would have been made to restore the exploded idea of man's supremacy over all other creatures in the universe... Nevertheless, a champion has actually appeared, who boldly dares to combat against all the rational inhabitants of other spheres." Whewell's stated goal was merely to demonstrate that there was no evidence that all planets are inhabited, which was certainly the case; but unfortunately he went beyond that and tried to prove that both science and religion supported the idea of Earth's uniqueness. This aroused the emotions of his opponents, and in some instances the published arguments degenerated into name-calling. However, the controversy did, for the first time, raise the question of whether life on other planets requires the same environment as it does on ours. This issue, and others based on increasing scientific knowledge, was to be of increasing importance from then on.

Such early speculations about ET life are not generally considered significant in the history of our culture. But I think they're important for two reasons. First, they show that the human mind has a tendency to believe in ETs even when no evidence is available, which has bearing on the nature of Space Age mythology. And second, having once taken hold ideas never really die out, so the fact that science rejected belief in ETs for a short period doesn't mean that the undercurrents of Space Age mythology haven't been present continuously. Science fiction is now that mythology's main expression, but it definitely wasn't its origin.

23. Scientists' Views of Extraterrestrial Life: Before World War II

In the late 19th century, belief in life on other planets--which had been nearly universal among educated people for two hundred years--began to decline. There were a number of reasons for this, but the major one was that for the first time, science was completely separated from religion. Always before, astronomers had used religious arguments to support the idea of life on other worlds; they maintained, as did everyone, that God would not make a useless planet. This was the majority view even at the time of the Whewell controversy in the 1850s. But later, as science came to rely exclusively on observation and experiment, such arguments could no longer be used; and, apart from new telescopic data showing unpromising conditions on nearby planets, there was no evidence one way or the other about extraterrestrial life. A 1882 popular astronomy book stated, "The spirit of modern science is wholly adverse to speculation on questions for the solution of which no scientific evidence is attainable."

That sounds very much like the spirit of today's science. However, there are some differences today. Now, we expect to obtain evidence in the future that we can't obtain at present, an attitude not yet prevalent in the 19th century. This expectation is particularly influencial with respect to the views of modern astronomers concerning ET life, as I'll explain below. Furthermore, today we are not discouraged by the same kind of disillusionment that shaped views of the universe around the turn of the century.

In 1855 one reviewer of Whewell's book on the plurality of worlds had made a prophetic remark. He had said, "If the planets are not made for inhabitants ... since some of them are of no use to us, and are not likely to be, it appears that there are things created without any use at all. And this is a dangerous element to admit upon so large a scale into our calculation of the evidence for design." At that time and earlier, avoiding this danger had not been considered an exclusively religious matter. As one American magazine put it, "Common-sense, popular instinct, so believes to-day, from its undoubting creed, that all things exist for USE." But as science advanced, it became obvious that there is indeed waste and "uselessness" in nature. An astronomer of the late 1870s, referring to "waste seeds, waste lives ... waste regions, waste forces" in our own world, suggested, "May we not without irreverence conceive (as higher beings than ourselves may know) that a planet or a sun may fail in the making?"

It's not possible to say just what role people's changing attitudes toward plurality of worlds played in early 20th-century skepicism toward pattern and purpose in the universe. It was partly a result of such skepticism, but also, perhaps, a partial cause. When people have been told for two hundred years that a cosmos full of perfectly ordered solar systems is evidence of the wisdom of its design, they do not like to hear about planets and suns having failed in the making.

In 1903 another important book argued that Earth is the sole abode of life; this was Man's Place in the Universe by Alfred Russel Wallace, best known for having developed the theory of evolution independently of Darwin. His views on extrasolar life were not widely accepted because, knowing considerably less about astronomy than about biology, he attempted to prove that our solar system is in the physical center of the universe and that only near the center can conditions be right for the evolution of intelligent life. However, he was better qualified to discuss life on other worlds within our solar system; his arguments against it demonstrated the difference between views of astronomers and biologists toward ET life that has existed ever since.

But for a short time during the first part of the 20th century, even astronomers maintained that ET life is rare. The reason for this was the theory of planetary formation then current, which held that planets were formed only when two stars passed so close to each other that matter was pulled out by gravitational tides. It was calculated that such an event could occur in our galaxy no more frequently than about once in five thousand million years. More impressive than this actual figure was the very concept of planets coming into being by accident rather than as part of a natural, universal process. The only grounds for believing that such a close approach of two suns might not be an accident were those connected with purpose in the universe, which had become, as one writer put it, "largely taboo in science today." Thus most people concluded that the evolution of life was wholly accidental. Sometimes the word "freak" was used, an exaggeration fostered by the popular works of the eminent astronomer Sir James Jeans, who wrote best-selling books for laymen. Although the tidal theory of planetary formation did predict the existence of some solar systems, almost everyone seems to have been overwhelmed by the huge proportion of planetless suns,

To most people, this was not a pleasant outlook. "We must make the best of it, even if we are doomed to undergo the worst of it," wrote one reviewer of Wallace's book. "It must be said, however, that this book ... is not a cheerful message, and we could wish it had been briefer. As one reads along its clear pages, and between the lines finds not only the doom of mankind, but the universe vacant of life ... one asks why the proof is piled so high ... So intolerable is the despair that settles upon us that we instinctively protest against Mr. Wallace's limitation... A planet may die, but a lifeless universe!--'that way madness lies.'"

The idea that suns change and planets do become unable to support life was another of the pessimistic ideas that advances in astronomy led to during the early part of this century, still another being the ultimate "running down" of the entire universe as a result of the Second Law of Thermodynamics. This prospect, combined with the disillusionment about our own culture caused by World War I and the Depression, made the era's outlook on the universe a dark one. Is it any wonder that this was the period during which science fiction arose, perhaps as a protest against a science that officially denied not only the prevalence of life, but hope for the distant future?

All this time, of course, from the origin of belief in ET life in the 17th century to its decline in the early 20th, there was absolutely no expectation of future contact between worlds. It was thought for a while, after the discovery of markings called "canals" on Mars, that further observation might lead to discovery of life there or even to signaling with lights, but this came to nothing. Occasionally someone said that rockets to the moon and Mars might become possible. A few far-sighted people speculated seriously about interstellar travel, notably the Russian scientist Konstantin Tsiolkovsky, who in the 1890s not only believed humanity will someday colonize other solar systems, but was the first to suggest the creation of orbiting colonies similar to those proposed in the early 1970s by Gerard O'Neill. (O'Neill did not learn this until after his own work appeared.) But Tsiolkovsky's work wasn't published till later, and wasn't translated into English until the 1960s. The American rocket pioneer Robert Goddard also speculated seriously about travel to other solar systems, but his manuscript on the subject was not published at all; he placed it inside a sealed envelope in a friend's safe, to be opened "only by an optimist."

It was not suggested outside of science fiction--and there only after the 1890s--that extraterrestrials might come to Earth, except for a few believers in interplanetary spirit travel by mortals (an idea now well established among occultists). Among these was the well-known Belgian writer Maurice Maeterlinck, who, in what was perhaps the earliest conception of ETs as "gods from outer space," reasoned that since no beings from other worlds have used their advanced science to abolish suffering on Earth, "Is there not reason to fear that we are for ever alone in the universe, and that no other world has ever been more intelligent or better than our own?" But this, the first serious "Where are they?" argument, was not known to the general public and in any case would not have carried weight, since it depended on the concept of disembodied spirits. Physical contact between worlds was not thought possible outside of fiction.

And this, I suspect, was a major factor in the increasing reluctance of science to acknowledge that there may be inhabited worlds. For scientists were no longer mere "natural philosophers," and the difference between scientists and philosophers is in the ability to gain new information. Scientists are not content to speculate; they want hard data, and if they cannot hope to obtain it, they are apt to tell themselves, unconsciously if not openly, that there is none to obtain. It is too painful to contemplate inaccessiblity. (I could name quite a few areas in which this principle appears to be operative, parapsychology being one of them.) This is a theory of mine that I have believed for many years--I can't claim to be able to prove it. However, it certainly fits the facts of this case. As I'll explain in the next lecture, what caused astronomers to reverse their views of ET life again was the idea of interstellar radio communication.

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Copyright 1995, 2003 by Sylvia Engdahl. All rights reserved.

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