Its meaning and allocation to subjects has changed considerably over historical time. Whatever the meanings offered, they have never included the tools used (e.g., developmental biology studies the development of multicellular organisms using whatever tools are available). By the 18th century, and following Gottfried W. Leibniz (1646-1716) who was reputed to be the last person to have known every discipline, there was a fragmentation of knowledge and a considerable increase in the number of disciplines. By the 20th century, Thomas Kuhn (1922-1996) contended that a discipline is particular scientific community, united by a common education, methods of accreditation, professional communication via discipline-specific journals and conferences as well as similar interests in problems of a particular sort and the acceptance of a range of solutions to them. A problem is to distinguish a discipline from something like a ‘field of study’. Primatology is perhaps a field of study as it is defined more by its object of study (viz., primates) than by the specific the subject matter it addresses. Thus, fields of study are defined by a common target of study, and subject-oriented disciplines by common goals, research questions, terminology and methodology. On this basis, both anthropology and psychology could be considered to be fields of study rather than disciplines, and, for example, developmental psychology as a sub-field of psychology.
See Anthropology, Biochemistry, Biology, Biophysics, Developmental biology, Developmental psychology, Inter-dependence, Interdisciplinarity, Interdiscipline, Levels of organization, Psychology