In scholastic logic, ''differentia'' (also called ''differentia specifica'') is one of the predicables; it is that part of a

definition A definition is a statement of the meaning of a term (a word, phrase, or other set of symbols). Definitions can be classified into two large categories: intensional definitions (which try to give the sense of a term), and extensional definitio ...

which is predicable in a given ''genus'' only of the '' definiendum''; or the corresponding " metaphysical part" of the object. In the original, logical sense, a differentia is a concept — the notion of "differentia" is a second-order concept, or a "second intention", in the scholastic nomenclature. In the scholastic theory it is a kind of essential predicate — a predicate that belongs to its subjects ''de re'' necessarily. It is distinguished against the

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

by expressing the (specific) essence of the object only partially and against the ''genus'' by expressing the determining rather than the determined part of the essence.

History

Ancient Greek philosophy Ancient Greek philosophy arose in the 6th century BC. Philosophy was used to make sense of the world using reason. It dealt with a wide variety of subjects, including astronomy, epistemology, mathematics, political philosophy, ethics, metaphysics ...

Plato Plato ( ; Greek language, Greek: , ; born BC, died 348/347 BC) was an ancient Greek philosopher of the Classical Greece, Classical period who is considered a foundational thinker in Western philosophy and an innovator of the writte ...

implicitly employed the concept of differentia when he conceived his method of ''diairesis''.

Aristotle Aristotle (; 384–322 BC) was an Ancient Greek philosophy, Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, a ...

was the first to use the term ''diaphora'' (διαφορά) in a systematic fashion; but he had no explicit theory about it, and his understanding of the term is controversial. ''

Adiaphora Adiaphoron (; plural: adiaphora; from the Greek (pl. ), meaning 'not different or differentiable') is the negation of ''diaphora'', 'difference'. In Ancient Greek philosophy In Cynicism, adiaphora represents indifference to the vicissitude ...

'' - the negation of ''diaphora'' - is an important term in

Hellenistic philosophy Hellenistic philosophy is Ancient Greek philosophy corresponding to the Hellenistic period in Ancient Greece, from the death of Alexander the Great in 323 BC to the Battle of Actium in 31 BC. The dominant schools of this period were the Stoics, the ...

. However, only in

Pyrrhonism Pyrrhonism is an Ancient Greek school of philosophical skepticism which rejects dogma and advocates the suspension of judgement over the truth of all beliefs. It was founded by Aenesidemus in the first century BCE, and said to have been inspired ...

does it appear to be a denial of Aristotle's notion of diaphora. A theory was only provided by Porphyry's explicit treatment of the predicables presented in his ''

Isagoge The ''Isagoge'' (, ''Eisagōgḗ''; ) or "Introduction" to Aristotle's "Categories", written by Porphyry in Greek and translated into Latin by Boethius, was the standard textbook on logic for at least a millennium after his death. It was compose ...

''. The elaborate scholastic theory of the predicables evolved οn the basis of Boethius' translation of the Isagoge, where the Greek term ''diaphora'' was rendered in Latin as "differentia". Although the primary meaning of "differentia" is logical or second-order, it may under certain assumptions have an ontological, first-order application. If it is assumed that the structuring of an essence into "determining" and "determinable" metaphysical parts (which corresponding to a differentia and a genus respectively) exists in reality independently of its being conceived, one can apply the notion "differentia" also to the determining metaphysical part itself, and not just to the concept that expresses it. This is common in

Scotism Scotism is the philosophical school and theological system named after John Duns Scotus, a 13th-century Scottish philosopher-theologian. The word comes from the name of its originator, whose ''Opus Oxoniense'' was one of the most important ...

, where the metaphysical parts are said to be formally distinct. If, on the other hand, any mind-independent structuring on the part of the essence is denied (like in

Thomism Thomism is the philosophical and theological school which arose as a legacy of the work and thought of Thomas Aquinas (1225–1274), the Dominican philosopher, theologian, and Doctor of the Church. In philosophy, Thomas's disputed ques ...

or Suárezianism), then the partitioning of the essence into a generic and a differentiating part must be considered as merely "conceptua", whereas the actual realities corresponding to the differentia and to the genus evade as really the same. These assumptions therefore do not permit any ontological application of the notion of differentia.

References

{{Catholic philosophy footer Scholasticism Definition Concepts in metaphysics

History

See also

References