BOOKS ARE BASIC: THE ESSENTIAL LAWRENCE CLARK POWELL, edited by John David Marshall (University of Arizona: $12.50). Author, editor, and for nearly three decades head librarian at UCLA, Lawrence Clark Powell never forgot the example set by the librarian he met in his childhood. When others (including his teachers) told him "No," Mrs. Keith, of the South Pasadena public library, always said, "Yes." The idea that librarians should love books and do everything possible to help bring books and readers together seems so obvious as not to need saying. But between the proliferation of computer and video hard and software on the one hand and the growth of administrative hierarchies on the other, perhaps we do need to be reminded that books and reading are, in Powell's words, "the realist of all reality," and certainly the heart and soul, the raison d'etre, of any library. This small book of quotations, garnered from Powell's articles, books, essays and reviews, is divided into four sections. Powell's memories of Mrs. Keith are included in the last section, "On Lawrence Clark Powell." His wise, succinctly expressed views "On Libraries and Librarians" form the second section, in which he reminds us that "the public library is one of the few places left where we can be private." The third section, "On Writers and Writing," expresses some of this Southwesterner's ideas about writing and landscape. And the opening section, "On Books and Reading," is filled with quotable quotes, including, "Books themselves need no defense. Their spokesmen come and go, their readers live and die, they remain constant." John David Marshall, who edited this engaging collection, is also a librarian, and of course provides a complete bibliography of Powell's writings, which, judged by this sampling, must be filled with lucidity and common sense.