At my age (I was born in 1899), I cannot promise--I cannot promise even myself--more than these few variations on favorite themes."" Borges need not be so apologetic, for these thirteen pinwheels of fable, philosophy, and autobiography spin brightly enough to stand apart from the shadow of The Aleph. Nor should he feel the need to explicate them, as he does in an afterword of ""hasty notes."" If anything, too many of these stories are crystal clarities rather than crystal clouds, transparencies instead of highly buffed but stubbornly opaque mirrors. An amusing sliver of academia rather too neatly spots the common denominator--vanity--that links an ambitious scholar with an ivory-towered one. A doppelganger encounter with a younger self at Harvard is saved from obviousness by its testy sang-froid and wry self-deprecation: ""We have not changed in the least, I thought to myself. Ever the bookish reference."" Similarly, Borgesian cool redeems a future-voyager's familiar, pessimistic forecast, while a metaphysical point is too clearly made out an old man's memory of first exposure to love and death, and a wisp of Borges-in-Love (with feminist ""Ulrike"" in York) is more precious for its rarity than for any lingering effect. Not that this is a see-through collection. Make what you will of a murky homage to H. P. Lovecraft or imaginary fragments from theological history (a sect that worshipped Jesus and Judas equally) and medieval tale-telling (a harp-singer's single word, ""wonder,"" imparts total understanding). But five are prime, if not sug generis, Borges. ""The Disk"" and ""The Book of Sand"" present paradoxes--the one-sided object, the infinite-paged book--with dazzling economy, a blessed refusal to comment, and precisely the right quiver of a smile. A court poet's enforced quest for honesty moves from irony (""I have made myself skilled in satire, which causes infirmities of the skin, including leprosy"") to true fairy-tale terror. ""Avelino Arredondo"" is most atypical, entering the mind of a Uruguayan political assassin as he numbs himself into action. And ""The Congress"" is a marvel, the rare Borges story that makes direct human contact while toying with fantasy--here, the doomed turn-of-the-century Congress of the World (one poor man, one beautiful woman, etc.) in Buenos Aires. A book full of stories like ""The Congress"" would be for everyone; like The Book of Sand, alas, no such book exists, and this see-sawing assortment reflects the cool-warm strengths and ice-cold limitations of an elusive master.