Isagoge
Quick Summary
The Isagoge is a work by Porphyry, a Neoplatonist philosopher who lived around the 3rd century CE. His Isagoge served as an introduction to the logical concepts of Aristotle. This work became a standard textbook in the Middle Ages, particularly through a Latin translation by Boethius.12
The Isagoge focuses on five key concepts used by Aristotle:
* Genus: A broad category (e.g., "animal").2
* Species: A specific type within a genus (e.g., "human").2
* Differentia: A distinguishing characteristic (e.g., "rationality" for humans).2
* Property: A characteristic shared by all members of a species.2
* Accident: A non-essential characteristic.2
Porphyry's logical classifications, often illustrated by the "Porphyrian Tree," significantly influenced medieval logic and the understanding of universals.12
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history of logicTransmission of Greek logic to the Latin West… and of Porphyry of Tyre’s Isagoge (“Introduction,” on Aristotle’s Categories), although these translations were not very influential. He also wrote logical treatises of his own. A short De dialectica (“On Dialectic”), doubtfully attributed to St. Augustine (354–430), shows evidence of Stoic influence, although it had little influence of its own.…
Read More… and of Porphyry of Tyre’s Isagoge (“Introduction,” on Aristotle’s Categories), although these translations were not very influential. He also wrote logical treatises of his own. A short De dialectica (“On Dialectic”), doubtfully attributed to St. Augustine (354–430), shows evidence of Stoic influence, although it had little influence of its own.…
Read More- history of logicSt. Anselm and Peter Abelard
… and De interpretatione and Porphyry’s Isagoge, together with the commentaries and independent treatises by Boethius.
Read More… and De interpretatione and Porphyry’s Isagoge, together with the commentaries and independent treatises by Boethius.
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AristotelianismRelationship to Neoplatonism…with a short introduction (Isagoge). The Isagoge, in fact, is only concerned with a simple and rather mechanical treatment of five concepts that had been much used by Aristotle. These were the concepts of genus, or kind (as animal is the genus, or kind, under which Socrates falls); species,…
Read More…with a short introduction (Isagoge). The Isagoge, in fact, is only concerned with a simple and rather mechanical treatment of five concepts that had been much used by Aristotle. These were the concepts of genus, or kind (as animal is the genus, or kind, under which Socrates falls); species,…
Read More- AristotelianismFrom the 9th through the mid-13th century
The study of Porphyry’s Isagoge, of Aristotle’s Categories and De Interpretatione, and of theological texts containing Aristotelian elements formed the basis, from the 9th century onward, of logical methodology (dialectic) in a wide number of fields. When applied to problems concerning the Trinity or the Eucharist, or in general…
Read MoreThe study of Porphyry’s Isagoge, of Aristotle’s Categories and De Interpretatione, and of theological texts containing Aristotelian elements formed the basis, from the 9th century onward, of logical methodology (dialectic) in a wide number of fields. When applied to problems concerning the Trinity or the Eucharist, or in general…
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