According to this author, library classification should be viewed in its broader context of the classification of knowledge--the orderly arrangement of thoughts and things for convenient reference. This has been an activity of man since his earliest days, when primitive man first classified animals and plants in the interest of food. Philosophers, including Aristotle and Roger Bacon, have always been concerned with the arrangement, not only of objects, but of knowledge, into definable catagories. Library classification--practical systems for the arrangement of books on shelves--has also existed since ancient times. Librarians have relied, in their arrangements, on the knowledge schemes created by philosophers. As knowledge, and the number of books, have increased, new library schemes have been developed. The 19th Century saw many such schemes, notably the Dewey system. Because of the dynamic nature of knowledge itself, library classification schemes are unlikely ever to be stabilized. At present, librarians are attempting to fill the gaps by creating special systems for individual subjects such as business and medicine. (SL)