In principle, there is no topic, no place, no people, no event or sequence of events about which an historical account cannot be written. While the most trivial and frivolous topics are ruled out by the canons of scholarship, there is nonetheless a vast body of material whose preservation can be justified on the theory that someday someone will want to trace the historical changes in it or relate them to another body of material. Such caveats do not necessarily apply to the product of historical analysis, however, for the accomplished history of any topic, place, sequence of events, and so forth may be justified as a portion of the cultural record of the society in which it existed. On the other hand, in the disciplines that accumulate knowledge by discovery of new data and revision of established principles, such as the physical and life sciences, the opposite is generally true. Working scientists are usually interested in the latest version of a book or the latest number of a journal.
Great effort goes into updating, revising, and keeping current.
Active investigators and teachers of science generally believe that most essential knowledge from the past is, for their purposes, adequately represented in text books, handbooks, and reference works. It appears, therefore, that the preservation problem is most pressing in the arts and humanities and, correspondingly for the reason cited, the choices of what to preserve or conserve are the most difficult. Approaches to Selection Ideally, a selection strategy would invoke the most informed and prescient scholarly opinion about the future importance of each individual publication. The scholarly community can be of great help in clarifying the requirements of research, advising on which materials are of little or no use, and which are essential for an academic discipline. Another approach, suitable for small segments of a scholarly field, is the use of an existing scholarly bibliography that presumably identifies the most significant work in, say, british empiricist philosophy or indic philology during a particular era when materials are known to be at greatest risk of embrittlement.