WHEN IT COMES to the paranormal, most scientists seem to fall into one of three categories: those so skeptical of its existence that they wouldn't be convinced by their own levitation; those certain the entire explanation lies in test tubes, EEGs and random-number generators, and those mystified into a state of permanent reverence.

Biologist Lyall Watson, author of several books that deal with the subject, belongs to still a fourth category. Careful investigation of such phenomena as ESP and psychokinesis have led him to the inescapable conclusion that some things in this world do indeed fly in the face of those tenuous constructs we like to call the laws of physics. But he believes that the laboratory approach can only take us so far toward an understanding of these paranormal occurrences. Instead of dazzling ourselves with their wonder and variety or denying their existence altogether, we can use them to broaden our understanding of ourselves and the world around us.

And that is just what Watson tries to do in his latest book, Lifetide, which attempts to take up some of the loose threads from the overspecialized jumble that is modern science, and weave them into a coherent model of life and the universe that does away with many of the unanswered questions plaguing current explanations. Drawing from disciplines as seemingly disparate as quantum mechanics, Jungian psychology and astrophysics, Watson takes the anomalies even our most advanced theories can't adequately explain - including many that would be considered paranormal - and uses them as orientation points to construct a radical and fascinating new picture of a unified, living cosmos, one where the dividing lines between observer and observed, between organism and environment, and even between thought and reality are hazier than most people would ever imagine.

Reading the book, one can't help but marvel at the sheer amounts of relevant information at Watson's command. Drawing on his training as a biologist as well as his work in fields as diverse as anthropology, medicine and paleontology, he lets fly with fact after fascinating fact, covering everything from the curious mating behavior of the bowerbird to his own participation in a Malaysian firewalking ceremony.

But the book is far more than just another believe-it-or-not collection of juicy tidbits. The examples are carefully chosen to illustrate a series of larger patterns that ultimately fuse together to form a new and intriguing way of looking at life and the universe. And Watson points these patterns out in language so rich and lively that at times the book seems as though it were written by a poet rather than a scientist. This is, as he puts it, a book about the Lifetide, "the whole panoply of hidden forces that shape life in all its miraculous guises...the eddies and vortices of nature that flow together to form the living stream."

A warning to occult buffs, however: Lifetide is not light reading, and neither does everything in it smack of precognition and poltergeists. Watson covers an astonishingly wide range of topics, devoting considerable space to such "earthbound" matters as the biochemical origins of life, the interspecies transfer of DNA by means of viruses and the principles of biological immunity. And some of the book's most interesting offerings are what might be called "soft anomalies" - everyday facts that seem relatively commonplace until their significance and ultimate oddity are pointed out.

For instance, to support his contention that natural selection operating on random genetic mutation couldn't possibly account for the ultraspecialized adaptations displayed by some species, Watson serves up the case of Aternaria servillei, a riverbank insect whose protective body markings perfectly counterfeit the figure of an alligator, complete with jaws and teeth. "This astounding example of insect sculpture," he points out, "can hardly be the product of sheer chance. The mechanism of evolution...must have been at work with some reference to the alligator."

This brings us to what is in a sense the book's central point. For if evolution is not random, then just what is it that provides the deliberate direction guiding it and, as Watson tries to show, many other aspects of life as well?

The answer, he suggests, lies with what he calls the "contingent system," a sort of collective unconscious of all living things, extended to include biological components, which moves to its own rhythms and purposes and "is a little like air pressure, invisible and yet always there, flexing its muscles and pressing tirelessly on every part of the biosphere."

Watson builds an admirable case in favor of the existence of such a contingent system, and believes that the eventual discovery of its parameters and properties will reveal it to be the source of much that we now call the paranormal.

But even this, he feels, will not solve the underlying mysteries of the Lifetide. As he puts it, "You can collect as many seawater samples as you like, but none will contain, nor tell you anything about, the tide.... Life is a pattern, a movement, a syncopation of matter; something produced in counterpoint to the rhythms of contingency; a rare and wonderfully unreasonable thing." CAPTION: Illustration, no caption, Jacket drawing by Braidt Braids