A habitual book-reviewer, inured to the idea that he has to review what is set before him by the publishing industry, must view with awe and envy Stanislaw Lem's collection of what the publisher modestly calls "perfect reviews of nonexistent books.

One service a good book review can perform is to relieve people of the necessity of reading the book under discussion. Lem has taken the process a step further; by reviewing nonexistent books, he relieves the writer (presumably Stanislaw Lem) of the necessity of writing them. He also evades neatly a perennial problem of the reviewer's trade: nasty letters from disturbed authors, or from people who have read the book and suspect that the reviewer has not. Presumably, we must accept the claim that these reviews are "perfect," since we lack evidence to the contrary.

So perfect is this self-contained literary vacuum, in fact, that one begins at length to wonder whether the reviewer, like the books and authors he discusses, may also be nonexistent. Stanislaw Lem, we have been led to believe, is a Polish writer of science fiction who has had nearly a dozen books translated into English and greeted with considerable critical acclaim in the past few years.

But somehoiw (like the writing) it all seems a bit contrived: a sciencefiction writer appearing virtually out of nowhere at the dawn of the space age and bearing a name that is the acronym of one of the most publicized space gadgets of the era. Stanislaw Lunar Excursion Module, indeed!

In the books he has chosen to invent for review, one sees frequently a family resemblance to such real books (by Stanislaw Lem) as "The Cyberiad" and "Memoirs Found in a Bathtub." Apparently he has a taste for reading (as he has for writing) books that push the novel up to and beyond its established limits, books that brood metaphysically on such subjects as the creation of life and of the universe, the differences between human and artificial intelligence, the labyrinths of illusion our mind creates in its search for certainty.

But for all the similarities, there is a considerable variety among the books reviewed in "A Perfect Vacuum." For example, "gigamesh," by Patrick Hannahan is an effort to out-Joyce the author of Ulysses while retelling the ancient Babylonian legend. There are at least 100 symbolic meanings in Hannahan's omission of the "L" in "gilgamesh," and besides a wealth of allegory it is intricately structured: Chapter X "if read backward turns out to be Freudianism explained in Aramaic"; "the pattern of the commas in Chapter VI is an analogue of the map of Rome" and several chapters are original musical compositions encoded in the letters of the author's prose.

The four works of nonfiction reviewed by Lem (each dealing with human evolution or the origin and laws of the universe) are the ones that most closely resemble his own fiction. In "The New Cosmogony" (an imaginary Nobel prize lecture rather than a book review), we are confronted with the perfectly plausible idea that the laws slowly being discovered by human science are actually the rules of a cosmic, eons-long game being played by older civilizations.

Even more disturbing is "Non Serviam," in which a scientist creates "personoids," analogues of human "personality "living" in a computer program, and is distressed to discover that after hundreds of generations they have developed a theology of which he is the subject.

These (unlike "Gigamesh," perhaps) are books that Lem certainly might have written in full rather than presenting them in the outline and brief quotes appropriate for a book review. But the essentials are all there, and they are surely more powerful because they are presented with such clarity and succinctness. "A Perfect Vacuum" demonstrates what some of us have long suspected: that a book review can be an autonomous work of art.