Genus proximum et differentia specifica
Genus proximum et differentia specifica is the abbreviated form of the scholastic formulation of the classic rule of definition "definitio fi (a) t per genus proximum et differentiam specificam". This rule, which goes back to Aristotle , according to which a definition has to be made by specifying the next higher genre and the specific difference, was canonical up to traditional logic in the 19th century. Even with John Locke (1632–1704) it was no different: “ [A] definition must consist of Genus and Differentia [.] ”
Genus proximum stands for the “next genus” (→ generic term ); differentia specifica for the “peculiar difference” (→ species difference ). “Genus” and “species” refer to the pair of generic / subordinate terms to be selected (see term types ) and not the specialist terms genus and species used in biology .
Example: The term “human” can be defined as a “rational living being”. “Living beings” stands for the superordinate species: Humans belong to the group of living beings - “reasonably gifted” for the characteristic difference: Of all living beings, only man has the ability to reason.
In contrast, the definition of humans as “living being walking on two legs” would be imprecise, namely too far, since not only humans but also birds, if they move on the ground, walk on two legs. The definition of the human being as a "state-forming living being" would be too narrow, since it does not include all human beings; because there are people who live together in social associations that do not have the character of states . In this respect, Aristotle 's word about man as a zoon politikon is not a definition, but a description of his being.
In this way of defining, what matters is the interplay of genus and differentia . What exactly becomes genus proximum and differentia specifica depends on the discourse universe and the distribution of the characteristics over the set of individuals to be classified; under certain circumstances there are several solutions, using the example of humans as “unfeathered bipeds” in addition to “rational living beings”. Because in the case where there are no thinking plants, intelligent mushrooms etc., the difference “reasonably gifted” is sufficient to cut out a term from the extensive gender “living beings” that includes all people and only people.
The classic genus / species characteristic definition leads to a hierarchical classification or presupposes this. This is illustrated in the arbor porphyriana .
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Genus (e.g. living being) |
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Type 1 (e.g. human) |
species-forming difference (e.g. reasonably gifted) |
Type 2 (e.g. animal) |
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Critique of the classic rule of definition
Various criticisms have been made against this rule of definition:
- Exclusivity
- The objection to the classic rule of definition is that it is not the only type of definition. But for Aristotle it was not the only possibility of definition.
- relativity
- The objection to the genus / species characteristic definition is that it depends on the current level of knowledge what is to be regarded as the next higher genus. Initially, this only means that one has to question every definition and that definitions are often perspective, ideological, theory-dependent statements. This problem affects other types of definitions as well.
- Inapplicability independent of essentialist metaphysics
- Ernst Cassirer objected to the Aristotelian logic of definition that it picks out their common features in relation to a set of objects and declares them to be properties of the genus . Aside from biology, this way of defining terms is misleading, for example if meat and cherries are grouped under the same genus because they are “juicy, red foods”. The Aristotelian logic of definition only makes sense against the background of Aristotelian metaphysics, because only this legitimizes the assumption of a generic entity under which individual cases can be grouped as types . The case is then understood as an expression or realization of the species being. One then sees in individual people the embodiments of a species that works through them. Because of the untenable nature of metaphysical assumptions, Aristotelian essentialism was replaced in large parts of philosophy by nominalistic definitions of terms (Popper, Kuhn, Lakatos, Rorty, ...).
- Insufficient objectivity
- The objection to the rule of definition is that it “defines an abstract concept by referring to even more abstract concepts”. It therefore “does not represent the cognitive process.” On the other hand, it must be said that the definition of the genus / species characteristic is based on a “class-logical operation of averaging” and therefore leads to a more precise definition. It is not without reason that colloquial definitions are mostly based on the genus / species scheme. The fact that it does not represent the cognitive process does not appear to be a defect if one regards it as a result of such a process that has to be justified.
- Limited scope
- The rule of definition is countered by the fact that it has "only a very limited scope". However, it should be predominant in everyday language.
- Inaccuracy
- The definition rule is "probably not applicable at all if you try to give the terms 'genus' and 'differentia' an exact meaning." However, it should be sufficient to interpret these as a generic term and a specific term.
- Binding to the Aristotelian ontology and conception of essence
- For Aristotle, the genus / difference definition was a metaphysical real definition of the essence of a thing. However, one does not have to follow this interpretation. A generic / species difference definition is also useful if one rejects the possibility of a definition of an essence.
In spite of these points of criticism, the classic definition rule is still “usable for a large number of cases [...] as a“ basic model ”.
literature
- Hartmut Westermann: Difference, more specific. In: Historical Dictionary of Philosophy . Vol. XI, Schwabe, Basel 2001, Col. 313-325.
Individual evidence
- ↑ a b Bernd Buldt: genus proximum. In: Jürgen Mittelstraß (Hrsg.): Encyclopedia Philosophy and Philosophy of Science. 2nd edition, Vol. 3. Metzler, Stuttgart / Weimar 2008.
- ^ A b c d e Wilhelm K. Essler: Introduction to Logic (= Kröner's pocket edition . Volume 381). 2nd, expanded edition. Kröner, Stuttgart 1969, DNB 456577998 , p. 249 f.
- ↑ Cassirer: Concept of substance and concept of function. 2nd edition, Berlin 1923, pp. 5-11.
- ↑ a b Reichenbach: Fundamentals of symbolic logic. 1999, p. 21.
- ↑ Thomas Zoglauer: Introduction to formal logic for philosophers. 1999, p. 19: "All colloquial definitions have the same structure (scilicet: the definition by genus proximum and differentia specifica)."
- ↑ Fischer Kolleg Abiturwissen, German (2002), p. 166.
- ^ Albert Menne: Definition. In: Krings, Baumgartner, Wild: Handbook of Basic Philosophical Concepts. 1973, pp. 268, 271.