Throughout the nineteenth century, apart from the division in theoretical sciences and arts, classifiers attempted to divide the sciences into two groups. Already they had before them the examples of Francis Bacon (speculative and descriptive) and Hobbes (quantitative and qualitative). For Coleridge, the sciences were either pure (Grammar, Logic, Rhetoric, Mathematics, Metaphysics) or mixed. Arthur Schopenhauer’s similar groups were called pure and empirical, Wilhelm Wundt in 1887 called them formal and empirical, Globot mathematical and theoretical, and the St. Louis Congress of Arts and Sciences (1904) normative and physical. made similar division of the sciences into abstract and concrete

[There has been] a widening of the field covered by the concept of “information”, both its theory and its practice. Information transfer has been put on a par with the transfer of matter and energy, as one of the primary natural processes.’

The most important characteristic of documentary classification is that it is concerned with subjects, not just entities of taxonomic classification. What is the nature of the specific subjects - the themes on which books, parts of books, articles or parts of articles are written? A study of book titles alone would suggest that literary subjects have simple names like 'War, Religion', 'Boats', 'Musica; pitch', 'Colour', 'Acridines', 'Wild flowers', and so on. But the study of articles on the documentation level reveals that such titles are simple in appearance only. Such a literary subject is in reality a complex aggregate of specific subjects, eahc which is the main theme discussed from one particular aspect.

The scope of a specialised documentary classification is usually designated by its title, the subject field that it professes to classify. It is no easy task to state what is meant by a subject field. In general it can be expressed as Thing-Activity. A definable group of things... is selected, and from the many relations in which they subsist a certain number are selected as relevant.

In the past, documentation has frequently been compared with librarianship, with some argument as to which comprehends the other. The field is more helpfully characterised if we take its scope to be all forms of document (i.e. any physical carrier of symbolic messages) and all aspects of their handling, from production to delivery. The document system then becomes very much wider than conventional librarianship – it includes publication and printing, distribution, some forms of telecommunication, analysis, storage, retrieval and delivery to the user.

An information system is an organisation of people, materials and machines that serves to facilitate the transfer of information from one person to another. Its function is social: to aid human communication. If we take this to mean all reception of signals by the human senses (sight, sound, small, touch, taste,...)- then communication is an incessant and essential accompaniment of all human activity. If we restrict the meaning of signals to flowing between people, much of the daily life of most of us is occupied by such interpersonal acts.

Information practice... consists of two activities that we may call diagnosis and prevention. Diagnosis is identifying what is the most probable information need of a user in a particular state of information want. Provision is deciding what action is most likely to meet that need. Information science seeks to understand the potential range of user situations giving rise to information want and needs; to develop methods of identifying the actual information needed; to understand and expand the range of possible ways of satisfying information need; and to develop methods of deciding what way is most likely to be effective in a particular case.

In seeking scientific understanding of the processes of information transfer we have had to go considerably outside the subject limits within which 'information science' as an academic subject is normally constrained... It has become increasingly clear that only by widening its “knowledge base” can information science establish a solid foundation for future development.

The basic rules of classification are - Each characteristic of division must produce at least two classes - Only one principle of division must be used at a time, to produce mutually exclusive classes. - The species of any genius must be completely exhaustive of their parent class.