The latter idea is to be found, for example, in the doctrine of the Yugas - or world ages - in the Mahabharata of India, wherein it is said that the first Yuga, the Krita, was the best, and that human society has been in decline ever since. The Maya and the Hopi told of a series of elapsed World Ages which ended, in turn, in flood, fire, and earthquake. In Western classical literature, Hesiod’s doctrine of the original Golden Race and the succeeding races of Silver, Brass, Heroes, and Iron relates essentially the same story. But of all the tales of lost or fallen worlds, perhaps none has exerted a greater influence on the popular imagination than Plato’s account of the island of Atlantis.

Writing in about 355 BC at about age seventy, Plato told of a great maritime civilization that had existed nine thousand years earlier, and located its center “beyond the Pillars of Heracles” (that is, the Strait of Gibraltar). He claimed that the story originated with the priests of Isis, who had imparted it to the Athenian statesman Solon during the latter’s trip to Egypt around 590 BC. The Atlanteans, unsatisfied with ruling their own land, had conquered parts of the outer “true” continent and much of the Mediterranean region, including Egypt. But they were defeated in their attempts at conquest by the brave Athenians, ancestors of Solon. Soon afterward, a great earthquake and flood caused Atlantis to sink beneath the waters of the ocean “in a single day and night.” Plato describes the lost city and island of Atlantis in detail and mentions Socrates’ enthusiasm about the story, which the elder sage termed “no invented fable but genuine history.”

Plato’s narrative, contained in the dialogues Timaeus and Critias, would eventually inspire over five thousand books seeking to explain away or to identify the sunken land. Nearly every place from Palestine to Brazil, from the West Indies to the North Pole has been suggested by one author or another as the “real” site of Atlantis.

Historians of the steady-progress school have argued either that Plato was exaggerating (perhaps, they say, Atlantis was merely the Greek island of Thera and did not sink 11,500 years ago but was destroyed in a volcanic eruption in 1500 BC), or that he made the story up in order to illustrate his political ideas or to convey through allegory some item of arcane mathematical or astronomical knowledge. After all, Plato’s narrative is not supported by any other early Greek or Egyptian document describing a lost island named Atlantis; moreover, we know that it was common for authors in his era to put invented speeches in the mouths of famous historical characters in order to illustrate competing philosophies. Of the thousands of dialogues surviving from ancient times, few if any are believed to be accurate transcripts of real discussions.

Plato’s story would likely never have stirred so much controversy had it not been for certain intriguing bits of evidence that have nagged at explorers and historians for centuries - evidence suggesting the existence of an unknown early civilization with highly developed scientific and engineering capabilities. Since conventional history supplies no likely candidate as source for such evidence, theorists have turned again and again to Atlantis.

The single most frequently cited item of evidence for a lost high culture is the Great Pyramid of Giza. Of the seven wonders of the ancient world, it is the only survivor. It consists of over two million blocks of stone, most weighing from two to six tons, though some are far heavier. Since the Great Pyramid is as tall as a forty story building, its builders faced the immense problem of lifting or dragging these blocks ever higher as construction proceeded. We still do not know quite how they did it, though theories abound. The largest construction cranes in existence today can barely lift 200-ton blocks, such as the ones in the core of the neighboring pyramid attributed to the pharaoh Khafre, and there is no construction company in the world that would undertake the job of duplicating either of these immense structures. The designers and builders of the Great Pyramid are conventionally credited with having only a rudimentary knowledge of mathematics and the most primitive of tools, yet the precision of their work is truly astounding, judged by any standards: many of the blocks are fitted to opticians’ tolerances, and the structure as a whole is square and aligned to true north to an accuracy that would be difficult to improve upon with even the most up-to-date surveying and construction equipment.

But the mysteries of the Great Pyramid go far beyond the engineering virtuosity it so magnificently flaunts. There is also the matter of its design. Historians of science maintain that the number pi - the ratio of the radius to the circumference of a circle - was discovered by the Greeks and worked out to the fourth decimal place by the Hindu sage Arya-Bhata in the fourth century. Nevertheless, pi is embodied in the ratio of the Pyramid’s height to the circumference of its base, and to a precision of five decimal places. The perimeter of the sockets at the base of the structure equals a half minute of equatorial longitude, or 1/43,200 of the Earth’s circumference; and the Pyramid’s height, including the stone platform on which it rests, equals 1/43,200 of the Earth’s polar radius. This suggests that the Pyramid’s builders had a good idea of the shape and size of our planet and intended the monument to embody this geodetic information.

Discussions about the Great Pyramid are inevitably littered with question marks. How? Why? When? Was the Pyramid built as a royal tomb, as nearly all the textbooks tell us? If so, why would anyone have gone to such immense lengths to build a permanent, conspicuous mausoleum, and then leave no epitaph? The tombs of most pharaohs are covered with hieroglyphs and cartouches; in the Great Pyramid there are no inscriptions whatever, save for a few workmen’s rough quarry marks on the inner blocks, from which Egyptologists have inferred that the builder was a Fourth-Dynasty pharaoh named Khufu. No body was found in the Pyramid, nor any unequivocal sign that a burial ever occurred in it. Not surprisingly, crypto-historians have always asserted that the Great Pyramid served purposes other than that of grave - including initiatory temple, geodetic marker, and signpost of the survivors from Atlantis.

The Pyramid is conventionally dated at about 2500 BC, which places its construction in the early phase of Egyptian history. Egyptologists acknowledge that the artistic and engineering achievements of the civilization peaked near its beginning; but given that there is so little evidence of gradual cultural development prior to the Pyramid Age, one has to wonder how these people so quickly acquired their skill and knowledge, and why they gradually frittered it away during the remaining two thousand years of their history. The Egyptians themselves apparently believed that their civilization had a much greater antiquity than present experts acknowledge, one that reached thirty millennia or more into the dim past.

While the Great Pyramid is perhaps the most spectacular item of evidence suggesting the existence of a lost high civilization, there are many others. Consider, for example, the great fortress at Sacsayhuaman, Peru, whose wall contains stones weighing up to 400 tons, cut with as many as twelve butting faces fitted precisely with their neighbors; or the 228-foot-high Black Pagoda in India, capped with a single slab estimated to weigh over 1000 tons; or the platform of the Temple of Jupiter at Baalbek in Lebanon, containing three blocks weighing 750 tons each. In each case we see an instance of a global pattern: the earliest stone monuments often seem to be the largest and most perfectly executed.

As if this were not problem enough for the steady-progress version of history, consider the really bizarre anomalies that conventional historians disregard altogether: an iron cup found embedded in an Oklahoma coal mine, a metal tube recovered from a 65-million-year-old chalk bed, a gold chain encased in a lump of Illinois coal, a grooved metal sphere taken from a Precambrian mineral deposit, a nail embedded in sandstone in Scotland. The deeper one digs, the more reasons one finds to think that the standard view of history omits some vitally important chapter in the human past.

Could the giant quarried and carved stones of the ancients be a legacy of Plato’s Atlantis? Unfortunately, while the evidence is suggestive, it is far from being conclusive. In the case of well-documented lost civilizations - such as those of the Mayas, the Mycenaean Greeks, or the Babylonians - archaeologists can point to a geographical homeland, reconstruct a common language and trace specific contacts with contemporaneous cultures. But with regard to “Atlantis”, none of this is possible. Connecting the Great Pyramid with Stonehenge or Macchu Picchu requires a tremendous leap of conjecture. But of conjecture, among Atlantis theorists, there has been no lack.

While we do not know for certain where Plato got the idea of Atlantis, its later evolution in literature is a matter of record. Plato’s famous pupil Aristotle apparently did not take the Atlantean passages in Critias and Timaeus seriously, though Poseidonius, Strabo, and Pliny the Elder seem to have done so. By the time of the Church Fathers, the story was accepted at face value, though rarely mentioned. During the Middle Ages, rumors circulated widely about lands in or beyond the Atlantic Ocean, populated by “the Cannibals that each other eat, The Anthropophagi, and men whose heads do grow beneath their shoulders.” Medieval maps featured legendary lands with names like Antilla, St. Brendan’s Isles, and Avalon; and, following Columbus’s fateful voyage, rumors of unexplored lands ran riot. Throughout the Age of Discovery (or the Age of Invasion and Genocide, depending on your point of view), maps were festooned with newly named islands, many the result of poor navigation, clouds, or eyestrain: Isle of the Demons, Drogio, Estotiland, Grocland, Frisland, the Island of Brazil, and so on.

More than a few people, from Francis Bacon in the sixteenth century to Alexander von Humboldt in the nineteenth, thought that the Atlantis narrative was an early reference to America. Eventually, however, it became clear that none of the Native American civilizations had visited Egypt or Athens, and Atlantis theorists began to view the Americas merely as yet more colonies of the lost continent.

One of the most knowledgeable of these theorists was Augustus Le Plongeon (1826-1908), the first explorer to excavate the Mayan ruins in Yucatan. Le Plongeon pieced together what he believed was a history of the mother culture in the Atlantic, the founding of its colonies in Central America, Egypt, and Greece, and its destruction by earthquake. He based his Sacred Mysteries Among the Mayas and the Quiches 11,500 Years Ago on his own translation of the Troano Codex, one of the few Mayan books to survive the Inquisition. But Le Plongeon was derided by the Americanist establishment for his flights of historical fancy, despite his demonstrated ability to trace the surviving Mayan Indian culture to its roots by learning the language of the people and participating in their shamanic rituals.

At around the time Le Plongeon was completing his explorations in Yucatan, American lawyer, newspaper publisher, and politician Ignatius Donnelly (1831-1901) published Atlantis: The Antediluvian World, a book that would eventually go through over 50 printings and provide fodder for generations of Atlantis researchers. Donnelly was a man of extraordinary energy and curiosity: before commencing his writing career he had been Lieutenant-Governor of Minnesota and member of the U.S. House of Representatives. After his electoral defeat in 1870, he returned to Minnesota, wrote books, went on lecture tours, served in the Minnesota state senate, helped found the Populist Party, and twice ran for Vice President of the United States on the Populist ticket. In Atlantis, Donnelly argued that the source of all civilization was an island in the Atlantic that “perished in a terrible convulsion of nature, in which the whole island sank into the ocean, with nearly all its inhabitants,” though not before establishing colonies in Egypt and Central America. Unfortunately, though his scholarship was wide-ranging, it was exceedingly careless, and the academic community never took Donnelly seriously.

Establishment historians were even more dismissive of James Churchward, author of The Lost Continent of Mu (1931). Churchward set out to prove that the ultimate source of civilization lay not in the Atlantic, but the Pacific Ocean, where a great continent called Mu had disappeared 13,000 years ago when “gas belts” supposedly underlying the continents collapsed, causing both Mu and (somewhat later) Atlantis to sink beneath the waves. Churchward said he had based his conclusions on the study of two sets of inscriptions, one in India and the other in Mexico. The Indic tablets were never seen by other researchers, and the Mexican ones - a collection of 2,600 carved stones found in 1921 by explorer William Niven, a friend of Churchward - have been virtually ignored by the authorities. A reconsideration of the significance of the Mexican tablets is long overdue, but Churchward is partly to blame for their neglect: The Lost Continent of Mu bristles with so many demonstrable errors in archaeology, history, and linguistics (for example, the frontispiece shows a “12,500-year-old Muvian jar” bearing an inscription which Sanskrit scholars recognize as dating from no earlier than the eleventh century) that the potentially useful material it contains has suffered from guilt by association.

By far the most colorful writing about Atlantis has come not from explorers or historians, but from clairvoyants and occultists - of whom the most influential was Helena Petrovna Blavatsky (1831-1891), the founder of Theosophy. Blavatsky claimed to receive telepathically the teachings of a group of Masters or Mahatmas, who for millennia have maintained a benign oversight of the world from their headquarters in Tibet and who purportedly showed her the manuscript of the Book of Dzyan (originally composed in Atlantis in the forgotten Senzar language). It was on the Book of Dzyan that Blavatsky would base her magnum opus, The Secret Doctrine, a vast synthesis of Eastern and Western myth and magic. According to The Secret Doctrine, humankind is destined to unfold through seven Root Races, of which we (humanity in the present era) are the Fifth. The Fourth Root Race was that of the Atlanteans, and the Third the Lemurians - who were hermaphroditic giants, some with four arms or an eye in the back of their heads. The people of the First and Second Root Races, it seems, were not entirely physical. According to Blavatsky, both Lemuria and Atlantis were destroyed when their populations resorted to sorcery.

Rudolf Steiner (1861-1925), the founder of Anthroposophy - an offshoot of Theosophy - expanded on Madame Blavatsky’s account of the Atlanteans and Lemurians in his own voluminous writings. The Lemurians, he said, operated on instinct and will power, by means of which they could control nature in extraordinary ways. The Atlanteans had better memories than the Lemurians, but did not develop rational thought (the contribution of our own Root Race); still, they were masters of the life force, by means of which they operated aircraft and built cities. They also used the occult power of words to heal and to tame wild beasts.

Edgar Cayce (1877-1945), “the sleeping prophet,” was famous for his ability, while in trance, to diagnose illnesses, often without benefit of any direct contact with the patient. During his “life readings,” in which he described his subjects’ past incarnations, he often referred to Atlantis and the events surrounding its destruction. The Atlanteans, according to Cayce, had air travel, electricity, advanced metallurgy and chemistry, detailed knowledge of geography, and standard units of measure. When it became apparent to Atlantean priests that their homeland was doomed, they sent colonists to carefully chosen sites around the globe. A priest named Ra Ta decided upon Egypt and began construction of the Great Pyramid in 10,490 BC, several centuries before the cataclysmic end of the Third World Age. Cayce described Atlantis as a group of large islands in the western part of the Atlantic Ocean, and prophesied that it would reemerge from the depths in the late twentieth century.

If most scientists were skeptical about the ideas of Le Plongeon, Donnelly and Churchward, they were even less inclined to seriously consider those of Blavatsky, Steiner and Cayce. By the early part of this century, geologists had determined that sea beds and continents are composed of fundamentally different kinds of rocks, and that there simply are no large areas of continent-type rock (known as sial for its silicon-aluminium content) present on the ocean bottom. Why, then, give credence either to ancient myths or to clairvoyant visions of ancient advanced civilizations of which there is no conclusive evidence, and that supposedly lived and perished on lost continents that could not have existed?

Still, there was the riddle of the stones. How and why did people in Europe, the Near East, and South America build astronomically aligned structures many millennia ago using giant monoliths? Where did they get the necessary engineering know-how? Throughout the present century, the depth of the mystery has steadily increased, while the skepticism of the scientific establishment has hardly abated.

Alsatian philosopher and mathematician R.A. Schwaller de Lubicz spent the years 1936 to 1951 in Egypt making painstaking measurements of the Temple of Luxor - which he characterized in his book, Le Temple de l’Homme as an architectural image of the human body, incorporating knowledge of the location of the ductless glands, the Hindu chakras, and the Chinese acupuncture points. These, together with astronomical alignments incorporated in the structure, showed symbolically the incarnation of the universe in human form. De Lubiscz contended that the science of the Egyptians (their mathematics, medicine, astronomy, and engineering) was far in advance of what can be explained by a slow, indigenous acquisition of knowledge, and must have been the legacy of some previous high culture.

In Maps of the Ancient Sea Kings: Evidence of Advanced Civilization in the Ice Age (1966), Charles Hapgood presented the fruits of his careful study of medieval and Renaissance maps showing coastlines that had not yet been “discovered.” These well-authenticated maps, some of which show an ice-free Antarctica as it would have looked many thousands of years ago, were purported by their creators to be copies of still older maps - which, Hapgood theorized, may once have been housed in the great libraries of Alexandria and Constantinople. Hapgood, a professor of anthropology and the history of science, deduced that the ancient geographical knowledge embodied in the maps could only have been accumulated by a maritime civilization prior to the change of sea levels that occurred roughly 11,500 years ago at the end of the last ice age.

In their brilliant and difficult book Hamlet’s Mill (1969), Giorgio de Santillana and Hertha von Dechend argued convincingly that the ancient, worldwide language of myth preserves archaic knowledge of the precession of the equinoxes - an astronomical phenomenon commonly believed to have been discovered by Hipparchus in 127 BC. The fact that the full cycle of the precession completes itself only once every 26,000 years suggests that humans may have been observing the sky systematically for a very long time indeed.

The work of de Lubiscz, Hapgood, and de Santillana, though stunning in its implications, raised only limited interest among scholars. Meanwhile, several popular writers of the 1960s and ’70s ignited a firestorm debate about crypto-history among the general public. In The View Over Atlantis (1969), which is still probably the best-written example of the Earth-mysteries genre, author John Michell suggested that traditional sacred sites in Britain (including Stonehenge, Woodhenge, Avebury, Glastonbury, and the “ley lines” connecting them) were planned according to principles similar to those encoded in the Great Pyramid, using a universal archaic system of measure. This, according to Michell, implies “a gigantic work of prehistoric engineering” laid out across the surface of the planet. In his book, Michell cited the research carried out by engineering professor Alexander Thom, who spent decades meticulously surveying the 500 or so stone circles of Britain, and concluded that their groundplans were based on a precise geometry and incorporated astronomical alignments related to the extreme positions of the Sun and Moon and the rising points of stars.

Books like Peter Tompkins’s Secrets of the Great Pyramid (1971) and Secrets of the Mexican Pyramids (1976), Brad Steiger’s Mysteries of Time and Space (1973), Otto Muck’s The Secret of Atlantis (1978) and William R. Fix’s Pyramid Odyssey (1978) combed over similar data and drew similar conclusions. But it was the wildly successful Chariots of the Gods (1970) of Erich von Daniken that led the way in book sales and controversy. By blending flying saucer reports with ancient stories about the exploits of various local deities, and adding more than a judicious dash of Earth-mystery lore, von Daniken arrived at the startling conclusion that God was an astronaut. Perhaps, he posited, Earth was visited in ancient times by explorers from other star systems, and humankind was put here as part of a cosmic science experiment. There is no way to completely disprove such an assertion; indeed, in competent hands it could be argued rather convincingly. Unfortunately, however, von Daniken heavyhandedly conflated genuine mysteries - like the Nazca lines of Peru - with phenomena that are well explained in quite mundane terms - such as the statues of Easter Island, whose creation has been reconstructed in detail by archaeologists - monotonously insisting on the same explanation in every case. Critics easily discredited him.

Zechariah Sitchen, author of The Twelfth Planet (1976), took up where von Daniken left off, contributing his impressive ability to translate Mesopotamian texts. According to Sitchen’s readings, the Sumerian gods Enlil, Enki, and Inanna were members of a race of ancient astronauts who came to Earth to mine gold. After genetically engineering human beings as servants, they interbred with their creations and taught them the arts of civilization. Eventually, the gods fell to fighting among themselves, brought on a catastrophe remembered as the biblical Deluge, and left humanity to cope with the aftermath. Sitchin doggedly ignored all contrary interpretations of the Sumerian literature, such as those of the late Joseph Campbell; Sitchin was as relentlessly technological as Campbell was metaphysical in his approach to the texts - whose “real” meaning is about as clear as that of a Rorschach ink blot.

By the late 1970s, the crypto-historical literature, though uneven, was extremely extensive. Evidence suggesting the existence of a lost high culture had been prodded and dissected by scores of authors with a wide range of prejudices and abilities. None - neither the sober scholars like de Santillana and Hapgood nor the careless sensationalists like von Daniken - had been able to persuade the scientific establishment to undertake a fundamental reassessment of the steady-progress version of history.

For New Age devotees, no further proof was necessary: Atlantis and Lemuria were already unquestioned realities, routinely discussed as the backdrop for this or that prior incarnation. But for those with a more skeptical bent - including the vast majority of scholars and scientists - it seemed that one last bit of unequivocal evidence was needed in order to turn the tide. If only someone could point to a piece of carbon-dated hardware stamped “Made in Atlantis”!

Attempts were made to uncover the crucial proof. During the mid-’70s, Cayce-inspired explorer Dr. David Zink investigated an underwater stone “road” near the island of Bimini, finding a tongue-and-groove pavement slab and other curiosities. But it was impossible to determine the date of construction, and further research was postponed for lack of funds. Even with this added, tantalizing piece of information, the contest between the crypto-historians and the defenders of the steady-progress version of the human past remained at an uneven and uneasy stalemate.