WHAT IS THIS Need to believe?

In a time when we can transplant hearts, restore severed fingers and sustain life with kidney machines, millions believe in something called psychosurgery, by which growths and cataracts are allegedly removed by sleight of hand and "X-rays" are taken by holding up a bedsheet in front of the victim.

In the era of Thor Heyerdahl's raft expeditions across the Pacific, his reenactment of the building and raising of the Easter Island monoliths, and the newly discovered proofs of how the Temple of Karnak and the Pyramids were built, Erich ("Chariot of the Gods") von Daniken sells 34,000,000 copies of books asserting that these wonders could only have been accomplished by superior beings from outer space. He even outsold Dr. Spock.

For a goggle-eyed television generation never exposed to parlor magic, wildly promoted "mentalists" and "psychics" perform tricks that a few decades ago were standard vaudeville turns. In fact, a New Jersey professional magician, James Randi, makes a career out of duplicating some of the mircales of Uri Geller using regular sleight-of-hand techniques.

In the teeth of great astronomical advances, with scientists measuring the magnetic force of bodies so distant their very existence is still theoretical, there is a multi-million-dollar business built around people who believe their lives are in the most literal sense ruled by medieval lore about stars and planets.

At a point in history when human beings have more power than ever before to change their lives and even their personalities with pills, psychotherapy, surgery and other techniques, millions spend their money on Biorhythms, a form of slide-rule Predestination. You can even buy an I Ching fortune-telling set that runs by computer.

"It's just amazing, this reversion to primitive credulity in the world's most technologically advanced country," said Paul Kurtz, a philosophy professor at the State University of New York at Buffalo who heads the Committee for the Scientific Investigation of Claims of the Paranormal.

Even before the release of the film "Close Encounters of the Third Kind," Kurtz predicted a new wave of UFO sightings. It's a case of suggestion, he indicated, like the so-called cattle mutilations in the Midwest and the pitted-windshields panic of the '60s.

(Last summer, drought-killed cattle were found to the missing eyes, tongues and genitals. Instead of concluding that small varmints had eaten these easily accessible delicacies, many Midwesterners preferred to believe the parts had been stolen for obscene rituals, presumably by UFO passengers. As for the windshields, a California newspaper started that one with a story about someone noticing his car windshield had tiny pits in it. Immediately, thousands of other drivers inspected their windshields carefully for the first time and found tiny pits. Conclusion: creatures from outer space were attacking them.)

"I think there are several reasons for all this," Kurtz said. "For one thing, there has been a lot of rapid social change recently. New technology, far greater mobility than ever, a loss of community roots. People are at sea. They move away from the old hometown to a new suburb, they get a job in a field that didn't exist in their father's day. There's a quest for meaning and purpose in life."

For another thing, he added, the visual media and even print media are pushing what has been called the New Nonsense with tremendous dramatic force.

"People are watching this stuff 35 to 40 hours a week: 'Star Trek,' 'The Bionic Woman,' the movies about Big Foot, the talk shows featuring psychics. It's all powerfully dramatized. And it's presented with great authority."

Kurtz's committee has just refiled its suit against NBC over a 90-minute special, "Exploring the Unknown," which last year dealth with psychic surgery, communicating with the dead and other subjects. The committee's charge is that NBC, while purporting to present a documentary, adopted a gee-whiz attitude that seemed to support the claims made.

"Their defense is that it's just entertainment," he said. "But we find it insidious. Would they do a program on Laetrile that showed only the favorable side? Sure, they had disclaimers stuck in there every now and then, but the point is, the stuff was packaged as truth."

The committee, including 43 scientists, educators and other ranging from writer Isaac Asimov to astronomer Carl Sagan to psychologist B. F. Skinner, is sponsored by, but independent from, the American Humanist Assn.

Formed in 1975 at Buffalo as an outgrowth of a petition by 186 scientists denouncing astrology as "chariatanism," according to The New York Times, the committee publishes a semi-annual magazine, The Skeptical Inquirer, formerly The Zetetic (Greek for skeptic), a curious mix of scholarly and popular writing.

Here is part of what the latest issue has to say about Von Daniken:

In his books, translated into 35 languages, the author describes a carved figure on a Mayan stele that he says must be an ancient depiction of an astronaut - "a man sitting, bending forward. He has a mask on his nose, he uses his two hands to manipulate some controls, and the heel of his left foot on a kind of pedal with different adjustments. The rear portion is separate from him; he is sitting on a complicated chair, and outside of this whole frame you see a little flame like an exhaust."

First of all, Zetetic suggests that viewers turn the "palenque Astronaut" drawing 90 degrees, which is the way it really appears, as confirmed by masks and other figures in the picture.

"When the illustration . . . is oriented correctly . . . we can see that the 'rocket' is actually a composite art form, incoporating the design of a cross, a two-headed serpent, and some large corn leaves. The 'oxygen mask' is an ornament that does not connect with the nostrills' but rather seems to touch the tip of Pacal's nose; the 'controls' are not really associated with the hands, but are elements from the profile view of the Maya Sun God in the background; the 'pedal' operated the astronauts' foot is a seashell, a Maya symbol associated with death, and the 'rockets' exhaust' is very likely the roots of the sacred maize tree . . ."

Von Daniken writes of a great prehistoric spaceport on Peru's Nazca Plain, scarred by some 13,000 lines and huge animal drawings discernible only from the air.

He says these had to be marks of a landing place for ancient UFOs: "At some time in the past, unknown intelligences landed on the uninhabited plain near the present-day town of Nazca and built an improvised airfield for their spacecraft," he writes in "Gods From Outer Space."

But why is it that "many of the lines run right into hills, ridges and the sides of mountains; the soft, sandy soil would not be a suitable surface for any kind of heavy vehicle to land on."

The magazine cites experiments by the International Explorers Society which showed that early Peruvians could have flown hot-air balloons over the site, using materials and techniques they were known to possess, to peruse the designs on the ground, believed to be an astronomical calendar.

Von Deniken insists that the Easter Island heads must be portraits of outer space beings since they don't resemble earthlings and that the hard volcanic rock couldn't have been carved by earthlings or lifted into place.

Heyerdahl found (in 1955, this was) that wetting the rock made it easy to carve. He point out that the faces do in fact resemble those of Easter Island natives. And he installed on of the 30-ton monoliths on an elevated platform using only levers, ramps and 12 men.

In brief, the ingenuity of ancient peoples has been grossly maligned, Zetetic holds, to make way for a theory of intervention by putative visitors from outer space.

It is the denial of what we know to be true that bothers the scientists. One story about the Bermuda Triangle decribes a freighter, the Sandra, as 250 feet long, and disappearing off Florida in June 1950 on a clam day. "The crewmen who had finished mess drifted to the aft deck to amoke and to relect upon the setting sun and what the morrow might bring," the popular account reads.

All right, a Zetetic investigator named Lawrence Kusche cheked with Lloyds of London. And he found this: The Sandra was only 185 feet long. June 1950 was indeed a tranquil time in the Bermuda area. But the ship did not sail in June. It sailed on April 5, from Sannah, Ga. On that day and the next several days the whole south-estern seaboard was buffeted by near-hurrican winds, which could very well have sunk the ship.

Hardly likely that anyone was having a smoke on the taffrail at such a moment, and anyway, Kusche asks, how would the author have known, if the ship disappeared with all hands? In the Charles Berlitz book "Without a Trace," celebrating the Bermuda Triangle, Christopher Columbus is supposed to have reported in his log "what appeared to be a fireball which circled his flagship." But if you look it up in Columbus's log, available in a good library, you find mention of a "great flame of fire" which dropped into the sea - but nothing about it circling the ship. That part was simply added, Kussche points out.

"What concerns us," Kurtz said, "is the way these things are being packaged and sold like deodorants. The same claim is marketed many different way: The Bermuda Triangle has turned up in books, a film, magazine articles, on TV."

Though the committee has crystallised a deep-seated concern among the country's scientists, Kurtz said, the paranormal fad is still growing.

"Before the development of the electronic media, we taught analytical skills in the scolls, we taught people how to read intelligently. Now there's this reversion to the spoken instead of written language. Everything is based on pure images, pre-verbal and pre-analytical knowledge. Images instead of concepts."

And whenever the media deals with the paranormal, the temptation is to take a favorable position, even if jocularly, he said.

James Randi, the magician who challenged Geller to a controlled test (but never got a reply) says the pro-paranormal books outnumber the debuntkers about 10 to 1 on the bookshelves and that even when a pseudoscientific book is debunked it continues to be offered for sale.

What Kurtz called "the psychic explosion" is one of three areas that the embattled committee is tackling. The other two are UFOs and astrology. It also keeps an eye on pyramid power, the Bermuda Triange, psychic medicine and the monster fad. Kurtz has a hard time understand why our picture-conscious nation is so easily satisfied with those few, fleeting, unfocused photos of Big Foot, that handful of decades-old flying saucer shots familiar to us all by now but still used to illustrate the newest saucer books.

"Of course I believe it's possible there are other forms of life in the universe," he said, "intelligent ones, too. But I'd like better proof than that."

One area of the paranormal which has attracted a good deal of serious attention is parapsychology, generally considered to include telepathy, clair-voyance, precognition and psychokinesis. Its most celebrated student is Dr. J. B. Rhine, whose tests at Duke University have covered a span of 40 years.

Though he has reported statistical evidence of the sixth sense that he named ESP, other scientists have had trouble duplicating his experiments. In 1974 his assistant and heir-apparent at the lab, Walter J. Levy, was forced out on charges of tinkering with the figures. (It is not an isolated case: An upcoming issue of the Journal of the American Society for Psychical Research will charge that results were changed in a 1941 telepathy experiment.)

Recently Rhine debated the subject with Kurtz at the Smithsonian Institution. One of their key points of contention was the so-called sheep-goat factor: Believers tend to get better results on the tests than skeptics, and subjects who score far above average in guessing flashcards for Rhine don't seem to do as well in a hostile or doubtful atmosphere.

"I believe ESP can exist," Kurtz said. "I know there are anomalies. Telepathy may be possible, and we don't know why some runs of predictions go beyond the rules of chance. We need new hypotheses, new sciences, we have to have open minds. But we need evidence. If you are going to present a scientific hypothesis, it must be replicable."

His investigative committee, which represents many different shades of opinion on the subject, has set up its own lab to test parapsychological claims.A girl from Buffalo demonstrated her precognition of playing cards in a session this spring, calling the cards before selecting them.

"It worked fine as long as she was holding the cards," he said, "but when we held the cards, she scored zero. Zero."

The experiments will be featured on an ABC special, "Closeup," next September.

Of course, a scientist shouldn't necessarily dismiss a subject merely because existing lab techniques don't bear it out. And many, many educated and intelligent people will swear that, experiments or no, there's something out there.

It would seem that virtually everyone in America had, or knows someone else who had, an experience with ESP. The most convincing instances involve "flinders." These can range from the strange lady down the street who found your mother's lost wedding ring to body-locators like Peter Hurkos and Dorothy Allison, a 53-year-old New Jersey woman who has made believers out of more than one skeptical policeman.

Allison is so well-known now that she was the first psychic called into the Patty Hearst case, but 10 years ago she was just another citizen to Nutley, N.J., police chief Francis Buel when she came to tell him about her dream of a drowned little boy.

She described the child right down to his shoes being on the wrong feet, and Buel was impressed because no description had been published. A month later the body was found, in a drain-pipe in a pond, as predicted. And his shoes were on the wrong feet.

Then there is the business of coincidence. Everyone knows the strange symmetrics of the Kennedy and Lincoln assassinations. But what about the Golden Matchbox story? This involves the Victorian actor Edward Sothern, who lost the box, a gift from the Prince of Wales, while for hunting in England. He had a duplicate made, and years later he gave it to his son, who in turn gave it to an Australian friend.

Twenty years passed. The son visited England, met his father's fox hunting companion and was told that that very morning a farmhand had plowed up the original matchbox. The son wrote his brother about the find. The brother read the letter to a friend he had just met.

The new friend pulled from his pocket - the duplicate matchbox, given to him by the Australian.

Is there some force at work here?

Quite another matter is the late Edward R. Dewey's lifelong study of cycles, which has been documented to a fare-thee-well. Dewey found thousands upon thousands of cycles, from animal and insect population to river runoff to cotton prices to war and disease incidence. Some cover eight years, some 9.2 years, some 9.6 or 13.2 years or more.

Putting them together on charts, he discovered that "all cycles of the same length tend to turn at the same time.They act in synchrony."

In "Cycles: The Mysterious Forces That Trigger Events," he writes: "If we have electromagnetic waves that come a trillionth of a second apart, a billionth of a second apart, a millionth of a second apart . . . why can't there be electromagnetic waves that come . . . a million seconds apart, a billion seconds apart? . . . A billion seconds would be between 31 and 32 years."

And how, he speculates, could we know of their existence except by observing their influence on earth? And what effect, even indirect, might they have on people, animals, plants, the weather and so on? Could they be related to ESP?

Writer Dan Greenburg, in a recent book, "Something's There," tells how he changed from a total skeptical to a respectful wonderer in the course of researching a story on black magic.

"It can be very frightening stuff," he said. "You hear some guy tell you about how you hurt your left ankle at 14 in ranch camp - well, that's not the kind of thing you put in your bio."

Ranging from Connecticut ghost tours to voodoo rituals in Haiti, from Loch Ness to satanist Aleister Crowley's home, he found much to scoff at - but also something else.

At a Chicago racetrack, a psychic predicted the first four winners for him and recited word for word a phrase that Greenburg was thinking, and a second phrase, and a third. Another time a psychic moved a pen across a carpet for him.

"I saw enough to convince me of the book's title," he said.

Another writer, Stephen Schwartz, will publish this August a book, "The Secret Vaults of Time," which he says will have "unimpeachable data" on psychic experiments. A year ago he organized the Mobius Group in Los Angeles, an interdisciplinary consortium of established scientists ranging from physicists to archeologists, and he claims astonishing success with triple-blind tests, all elaborately documented, in 14 countries.

There are plenty of mysterious goings-on around us. But it is not apparently the purpose of Zetetic and other skeptics to attack mysteries per se. There are more concerned with the people who us e the unexplained - and even the once-explained - to get money and power.

"If people believe in occultism," New Times magazine quoted science writer Martin Gardner, "you're paving the way for the rise of a demagogue."

Kurtz tells of running across a spaceage religion at Morningland, near San Diego, run by a seer named Sri Patricia.

"It was big on astrology and telepathy, and it had its own hymns, and its symbol was a pyramid, as in pyramid power. It seemed to work in all the fads. The basic idea was that Mohamed and Jesus and Moses were all visitors from UFOs. Our space brothers."

Is this why we are seeing a resurrection of obsolete mysteries, mysteries already solved? Is it a search for power over the believers, the power of those ancient wizards and medicine men who could predict eclipses or even just the spring equinox? Even if such a one scorned to claim the event as an expression of his own will, an aura would surround him, and his followers would told him in awe as a confidante of the unknown.

Notice, Kurtz says with a slow shake of his head, the religious undertone of "Close Encounters," the clearly spiritual intent of The Force in "Star Wars."

There is more than money at stake in the exploiting of this new need to believe.