Let us admit at the outset that there is absolutely no book that may not find its place on the shelves of some library and perform there its appointed function. From this point of view every printed page is a _document_, a record of something, material, as the French say, _pour servir_; from a mass of such material neither falsity, immorality nor indecency can exclude it. I do not speak at this time, therefore, of the library as a storehouse of data for the scholar and the investigator, but rather of the collection for the free use of the general public and especially of collections intended for circulation. It is to these that the censorship to which I have alluded may properly apply and upon these it is generally exercised. I know of no more desirable classification of books for our present purpose than the old three categories--the Good, the True, and the Beautiful. Those books that we desire, we want because they fall under one or more of these three heads--they must be morally beneficial, contain accurate information or satisfy the esthetic sense in its broadest meaning. Conversely we may exclude a book because it lacks goodness, truth or beauty. We may thus reject it on one or more of the three following grounds; badness--that is undesirable moral teaching or effect; falsity--that is, mistakes, errors or misstatements of fact; and ugliness--matter or manner offensive to our sense of beauty, fitness or decency. The first and third qualities, badness and ugliness, are often wrongly confounded, and as I desire therefore to speak of them together, we will now take up the second, namely, falsity or lack of truth. Strangely enough, among all reasons for excluding books this is perhaps least often heard. Possibly this is because it applies only to non-fiction, and apparently in the minds of many non-fiction is desirable simply because it is what it is. Again, the application of this test to any particular book can generally be made only by an expert. The librarian needs no adviser to tell him whether or not a book is immoral or indecent, but he cannot so easily ascertain whether the statements in a work on history, science or travel are accurate. This lack of expert knowledge is bad enough when inaccuracy or falsity of statement is involuntary on the author’s part. But of late we have in increasing numbers a class of books whose authors desire to deceive the public--to make the reader take for authentic history, biography or description what is at best historical fiction. Again, the increasing desire to provide information for children and to interest the large class of adults who are intellectually young but who still prefer truth to fictitious narrative, has produced countless books in which the writer has attempted to state facts, historical, scientific or otherwise, in as simple, and at the same time as striking, language as possible. Unfortunately, with some noteworthy exceptions, persons with