Absolute consistency in the matter of author entry may be attained by strict adherence to the A. L. A. rules, and the divergences from these rules necessary to adapt them to the varying conditions of public circulating, reference and university libraries are slight and unimportant. But who can frame a code of rules or formulate principles through which consistency in subject headings may be attained? And is consistency so absolutely necessary or desirable? Is not the ideal catalog the one which is best adapted to the needs of the majority of its users; which is so arranged that the reader can find what he wants in the shortest possible time, even at the sacrifice of absolute consistency? When the work of revising the Subject headings was begun, an effort was made to learn the wishes of all interested in regard to the principles upon which the new edition should be based. Many of you remember the list of questions that was published in the Library journal and in Public libraries. Some of you sent answers to those questions. They were questions of scope, of principle of selection, and of arrangement. The answers received from librarians, catalogers and reference workers, the opinions of members of the advisory committee upon these and other problems, the ideas expressed by library workers consulted by Miss Crawford in the various libraries which she visited, the suggestions gleaned from correspondence with other library workers and with experts upon various subjects, were all carefully noted by Miss Crawford, and in some instances tabulated so that the varying opinions could be seen at a glance. These notes, together with lists of headings from many libraries, large and small, made up the material from which the third edition of the Subject headings was compiled. The most casual examination of this material revealed the fact that while on some points there was practical unanimity of opinion, upon others there was the greatest diversity. The following are not exact quotations, as I no longer have the correspondence at hand; but they fairly indicate the opposing views of some of the writers: "Expand the list by the addition of necessary new headings, but make few if any changes. The A. L. A. headings are in very general use, and the possible advantage of changes would not compensate for the inconvenience and expense of wholesale alterations in existing catalogs." "The old headings are antiquated. Do not hamper libraries yet to be by perpetuating phraseology that no longer conforms to modern usage." "For the sake of uniformity, adopt the Library of Congress headings, even if not always entirely satisfactory for a public library." "The Library of Congress headings are not at all adapted for use in popular libraries. Disregard them." "The public library is for the plain people,--use headings they will understand."