NOT MANY NEWSPAPERS have Sunday book sections these days; a couple of brief reviews courtesy of the wire services is usually the extent of it. Not many of those that do have such sections will have anything to say about the work of Theodore Sturgeon, who died of lung disease last week. Sturgeon, after all, was only a science fiction writer. In the pantheon of modern fiction, where distinctions of subject have hardened into a critical mindset almost as arbitrary and complete as the Hindu caste system, that means Sturgeon occupied a place on the literary ladder one rung above writers of westerns and one rung below the writers of mysteries.

Only a science fiction writer. But his often tender explorations of alien minds were as carefully worked out as Faulkner's exploration of the mind of Benjy, the idiot in The Sound and the Fury. Sturgeon's emphasis on psychology instead of blasters prepared the way for such modern masters of the genre as Robert Silverberg, Gregory Benford, John Varley, Kate Wilhelm. When science fiction made its crucial shift from pulp action to a careful consideration of what the future might hold for the emotions and the psyche as well as for the techno- toybox, Sturgeon was in the van.

Only a science fiction writer, but in "Baby is Three" (part of More Than Human) and The Dreaming Jewels he brought Joycean stream-of-consciousness techniques to a field which until 1954 or so had considered the prose styles of such stalwarts as E.E. "Doc" Smith and Ray Cummings perfectly adequate.

Sturgeon and Philip Jos,e Farmer (who is also only a science fiction writer) broke the sex barrier almost by the themselves during the 1950s -- almost alone of their kind they dared propose that the sex life of science fiction might be more than cover deep. Sturgeon did it with Some of Your Blood, a giddy bravura tale of a vampire who drinks not from the jugular to kill but from the menstrual flow . . . as an act of love.

His stories in fact defy categorization -- beyond that implied by the Richard Powers paperback covers or the Virgil Finlay magazine illustrations, that is. He did in fact write horror stories as well as science fiction; long before Steven Spielberg's Duel or my Christine, Ted Sturgeon had linked the power train of an engine to fantasy in the nightmarish "Killdozer." He wrote social comedy satirizing the racial strife of the 1950s and early 1960s by creating love affairs between earthlings and aliens. He fulfilled the pulp dictum to create story before all else but the stories he created were told in an often transcending prose that almost sang as well as simply telling.

Only a science fiction writer was all Theodore Sturgeon was. Check the obits and see if I'm not right. But he also entertained, provoked thought, terrified, and occasionally ennobled. He fulfilled, in short, all the qualifications we use to measure artistry in prose.

Perhaps the best comment on how quietly such a fine writer can pass from us -- like an intelligent and witty guest who slips from a party where many less interesting folk are claiming greater attention by virtue of greater volume -- is this: Book World okayed a piece by Ray Bradbury, Harlan Ellison or me. By someone better known than Ted himself. A noisy party guest.

Considering the fact that he was only a science fiction writer, Theodore Sturgeon left exceedingly fine work behind him. Who knows? That work may be read and enjoyed long after the category itself has ceased to guarantee instant dismissal. That would be very fine.