Organon


 * This article is about Aristotle's logical works. For other meanings of the term 'Organon', see Organon (disambiguation).  For a discussion of Aristotelian logic as a system, see term logic.

The Organon is the name given by Aristotle's followers, the Peripatetics, for the standard collection of six of his works on logic. The system of logic described in two of these works, namely On Interpretation and the Prior Analytics, often called Aristotelian logic, is discussed in the article on term logic.

Constitution of the texts
The order of the works is not chronological (which is now hard to determine), but was deliberately chosen by the Peripatetics to constitute a well-structured system; indeed some parts of them seem to be a scheme of a lecture on logic. The arranging of the works was conducted by Andronicus of Rhodes around 40 BC.

Aristotle's Metaphysics has many points of intellectual overlap with the works making up the Organon, but is not traditionally considered part of it; additionally there are works on logic attributed, with varying degrees of plausibility, to Aristotle that were not known to the Peripatetics.

Categories
The Categories (Latin: Categoriae) introduces Aristotle's 10-fold classification of that which exists. These categories consist of substance, quantity, quality, relation, place, time, situation, condition, action, and passion.

On Interpretation
On Interpretation (Latin: De Interpretatione) introduces Aristotle's conceptions of proposition and judgement, and treats contrarieties between them. It contains Aristotle's principal contribution to philosophy of language.

Prior Analytics
The Prior Analytics (Latin: Analytica Priora) introduces his syllogistic method, which is discussed in the article on term logic, argues for its correctness, and discusses inductive inference.

Posterior Analytics
The Posterior Analytics (Latin: Analytica Posteriora) discusses correct reasoning in general.

Topics
The Topics (Latin: Topica) treats issues in constructing valid arguments, and inference that is probable, rather than certain. It is in this treatise that Aristotle mentions the idea of the Predicables, which was later developed by Porphyry and the scholastic logicians.

On Sophistical Refutations
On Sophistical Refutations (Latin:De Sophisticis Elenchis) gives a treatment of logical fallacies, and provides a key link to Aristotle's work on rhetoric.

The influence of the Organon
Aristotle's works on logic, (collectively called the Organon), are the only significant works of Aristotle that were never "lost"; all his other books were "lost" from his death, until rediscovered in the 11th century.

The Organon was used in the school founded by Aristotle at the Lyceum, and some parts of the works seem to be a scheme of a lecture on logic. So much so that after Aristotle's death, his publishers (e.g. Andronicus of Rhodes in 50 BC) collected these works.

In these works we can find the first ontological category theory (relevant in some branches of intensional logic), the first development of formal logic, the first known serious scientific inquisitions on the theory of (formal and informal) reasoning, the foundations of modal logic, and some antecedents of methodology of sciences.

The Organon was not always popular during the Hellenistic era. Stoic logic was predominant, particularly the work of Chrysippus (none of whose work has survived).

In the 8th century the Scholastics, in non-Arab Europe, studied and promoted the study of logic based on the Organon. One of the greatest Scholastics was Dominican monk Albertus Magnus (1206–1280), the teacher of Thomas Aquinas (1226–1274).

The books of Aristotle were available in the Arab Empire and were studied by Islamic and Jewish scholars, including Rabbi Moses Maimonides (1135–1204) and Muslim Judge Ibn Rushd (1126 - 1198); both lived in Cordoba, Spain. Cordoba had 70 libraries, one of them with over 40,000 volumes; the two largest libraries in non-Arab Europe each had only 2,000 volumes. Thomas Aquinas used the writings and comments of Aristotle ("the philosopher"), Albert, Maimonides ("the Rabbi") and Ibn Rushd ("the commentator") and many others.

In the Enlightenment there was a revival of interest in logic as the basis of rational enquiry, and a number of texts, most successfully the Port-Royal Logic, polished Aristotelian term logic for pedagogy. During this period, while the logic certainly was based on that of Aristotle, Aristotle's writings themselves were less often the basis of study. There was a tendency in this period to regard logical inference as trivial, which in turn no doubt stifled innovation in this area. Immanuel Kant thought that there was nothing else to invent after the work of Aristotle, and a famous logic historian called Carl Prantl claimed that any logician who said anything new about logic was "confused, stupid or perverse." These examples illustrate the general tendency during the period between the 13th century and the 19th century to accept without question the work of Aristotle. He had already become known by the Scholastics (medieval Christian scholars) as "The Philosopher." The dogmatism created by the Scholastics in favor of Aristotle took a long time to disappear.

Since the historical discoveries and logic innovations of the 19th century, particularly the discovery of Indian logic, George Boole's algebraic logic and the formulation of predicate logic, Aristotelian logic no longer has such prestige and is mainly studied out of historical interest. There is, however, a mostly pedagogical interest in term logic deriving from its close structure to the actual forms of reasoning encountered in natural language.