Melvil Dewey is the inventor of the Dewey Decimal System of Classification, which is used in most local and school libraries to catalogue books. Devised in 1876 as a system for small libraries, the system is based on ten classes of subject (000-999), which are then further subdivided.
The Dewey system has ten main classes, which are listed below.
000 Generalities
100 Philosophy and Psychology
200 Religion
300 Social Science
400 Language
500 Natural Science and Mathematics
600 Technology (Applied Sciences)
700 Arts
800 Literature
900 Geography and History
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