Every serious book of non-fiction should have an index if it is to achieve its maximum usefulness.
— The Chicago Manual of Style, 14th Edition
All nonfiction books should have an index to enable readers to find information quickly and easily. Indexes are tools of accessibility. If they are poorly made and cannot do the job for which they are intended, they frustrate the readers. Simply put, a bad index diminishes a book. Even those publishing houses that require authors to provide their own indexes recognize that the majority of them lack the objectivity, the training and the time essential for this vital task.
— Barbara Horn, The Effective Editor’s Handbook (1997)
Some books live or die by their indexes. An index can be the determining factor in whether a reference book is useful ... The Anglo-American tradition of serious writing and publishing calls for an extensive “scholarly apparatus” (indexes, footnotes, citations, and bibliographies) and it is always a shock to read continental European, especially French, books that lack footnotes or indexes ... Indexing cannot be mechanized and its largely anonymous practitioners need much flair and intuition to accompany the automated approach. Pity the poor indexer! Most readers take good indexes for granted and curse bad ones and, in either event, give little thought to the people who created them.
— Michael Gorman, Our singular strengths: meditations for librarians (1998)
I suspect that the continued production of indexless books is simply due to a mixture of parsimony and slovenliness.
— Alan Brien, Sunday Times (23 February 1969)
Sir, my friend John Baynes used to say that the man who published a book without an index ought to be damned ten miles beyond Hell, where the Devil could not get for stinging nettles.
— Francis Douce, in Henry B Wheatley, What is an Index? A Few Notes on Indexes and Indexers (1879)
no writer is so much read as the maker of a good index — or so much cited.
— Henry Rogers, in Henry B Wheatley, What is an Index? A Few Notes on Indexes and Indexers (1879)