BOOK REVIEW : The Dawning of the Legends and Lore of Earthly Paradise : DAWN BEHIND THE DAWN: A Search for the Earthly Paradise, <i> By Geoffrey Ashe</i> , Holt, $24.95

For anyone whose dark night of the soul happens to coincide with the hours between midnight and dawn, a balm is to be found on KPFK, where Roy of Hollywood plays hour upon hour of soothing discourse on the Big Bang, the Buddha nature, the magic mushroom and other flashes of enlightenment.

At 3 in the morning, it’s somehow comforting to hear the secrets of the universe revealed and the cosmic mysteries explained--and, somehow, even the wackiest notions seem reassuringly matter-of-fact.

Roughly the same phenomenon is at work in “Dawn Behind the Dawn,” a ramble through the legend and lore of paradise on Earth, from Shambhala to Eden and Atlantis.

We may find ourselves in a blighted and benighted era, but Geoffrey Ashe insists he can pinpoint the site of the original Garden of Eden--and he insists, too, that the earthly paradise was not less than the font of “Ancient Wisdom,” a body of esoterica that has endured over the centuries beneath the veneer of civilization.

“The Ancient Wisdom belief, or will to believe, peers back into the past,” writes Ashe. “Much of its allure springs from a sort of long-range nostalgia allied to the theme of a golden age or lost paradise. It now appears that . . . a reality may underlie it.”

Ashe, who has written several books on the Arthurian legend and “Ancient Wisdom,” suggests that the global myth of a lost paradise actually refers to a “garden of the gods” that existed in the lands between the Altai Mountains and Lake Baikal in what is now Siberia.

According to Ashe, “a shamanic package” of wisdom and magic--the goddess cult, the holy power of the number 7, the golden mountain that links heaven and Earth, and so on--bubbled out of Altai-Baikal and seeped into the very consciousness of humankind, where it lingers even in our own times.

Ashe’s book is garbed in the mantle of science, but it’s a soft-focus science that fairly shimmers with New Age sentiments. He invokes some of the more respectable popularizers of myth and legend: Robert Graves, Mircea Eliade, Joseph Campbell.

He moves on to Madame Blavatsky, whom he bravely defends as “more than a negligible crank,” and even to Erich von Daniken. But when he cites “the noted Californian witch Starhawk,” we know that we have passed through the looking glass.

Ashe dances nimbly through a dozen mythologies, touching down lightly in the Book of Proverbs and the Mahabharata and the Epic of Gilgamesh, Homer’s “Odyssey” and Dante’s “Inferno” and Milton’s “Paradise Lost.”

Out of the threads that he gathers from these and many other works, Ashe manages to weave a seamless argument in favor of Altai-Baikal as “a cultural seedbed” of world civilization.

For example, Ashe discerns a secret reference to Altai-Baikal in Psalm 48 (“I will sit on the mount of assembly in the far north”) and Ezekiel (“Behold, a stormy wind came out of the north”), and he searches out the same meanings in the nooks and crannies of Greek myth: Apollo, he points out, sojourned among the Hyperboreans, “whose name means ‘dwellers beyond the North Wind.’ ” Be warned: “Dawn Before the Dawn” is full of this kind of stuff.

Ashe allows as how the very idea of an earthly paradise may be just so much wishful thinking, “a universal quirk of human psychology.” But it’s clear that he doesn’t really believe it: Ashe comes across as a true believer who is convinced by what he has found in the ancient texts and traditions: “Clues hinting at something unprovided for in official prehistory.”

Mindful of the skeptical reader, for instance, Ashe concedes that numerology--a key element of his book--is a “kind of jugglery.”

But then he embarks gleefully on a elaborate effort to prove that the supposedly magical properties of the number 7 (“the supreme heptad,” as he calls it) amount to hard evidence of the enduring influence of the ancient Altai-Baikal shamans.

Ashe’s prose has an odd rhythm, at times lilting and rhapsodic, but mostly dense with earnest multicultural cross-references and relentless academic name-dropping.

Still, there’s something hypnotic in Ashe’s insistent patter about Ancient Wisdom and the Golden Age: “Dawn Before the Dawn” may seem more than slightly preposterous in the cold light of day, but at 3 in the morning, the whole unlikely affair--bear-worship, magic 7s, and all the rest--almost begins to make sense.

Next: Richard Eder reviews “The Lost Land” by W. S. Merwin (Alfred A. Knopf) .