Especially in this function sociological aspects are very important. Subjects mentioned in classifications For bibliographical classifications it is typical that not all subjects that are possible in theory, are mentioned in the schedules. Hulme stressed that subject-matter is almost indefinitely divisible. For the power of the mind to frame distinctions is practically without limits. A classification based upon this principle would in practice lead to a universal index of minutely divided subj ect headings and to the abolition of all general headings a scheme revived from time to time by indexing enthusiasts, but which for library purposes may safely dismissed as an economic absurdity.
Literary warrant is of course a sociological phenomenon.
What is published is more or less dependent on what referees recognize as worthwhile. Referees are part of the scientific community and influenced by the opinions in this community. Classification systems are made from yesterday s concepts of the dominant paradigms. There is no easy way out. It is impossible to predict the future scientific, technical and social developments.