The Isagoge ( ancient Greek εἰσαγωγή, eisagogé: " Introduction") is a short introduction to the font categories of Aristotle, the Greek philosopher Porphyry wrote in the 3rd century and had great significance for philosophy in the Middle Ages.


In the Isagoge Porphyry explains five interconnected basic philosophical terms, the so-called predicables:

At the very beginning of Scripture formulated Porphyry regarding the distinction between species and genera of the Aristotelian Topik those three questions, which staked out the frame of the medieval problem of universals:

However, Porphyry answered these questions not expressly.

Their discussion began only in Boethius, who translated the Isagoge twice into Latin and extensively annotated. Since this and other Latin transfers the font voces also titled Quinque ( Latin for " five words" ) is known. In the medieval West was the Isagoge in Boethius ' translation of the most important introductory manual logica vetus ( "old", that is, Aristotelian logic). A similar effect achieved in the Arabic -speaking Arabic translation that Abu ' Uthman ad - Dimashqi anfertigte to 900. More translations into Latin, Syriac and Armenian are known; overall the writing was more than twenty times commented and used until the 12th century as an introductory textbook.

Model of human knowledge

In connection to the Isagoge the metaphor of the arbor porphyriana was coined in the Middle Ages. The arbor porphyriana represents the systematic classification of genera and species as a recursive tree

The arbor porphyriana is also the discussion of philosophical problems:

  • Problems of metaphysics (which counts as a species? Than what kind? What the difference? )
  • Problems of universals ( metaphysical and epistemological aspects)

Same works by other authors

  • Albinus, a philosopher ( Platonist ), written in the 2nd century a previously known as Isagoge, nowadays usually called Prologue Introduction to the Platonic philosophy.
  • Constantinus Africanus, a Benedictine of the 11th century, produced a Latin translation of an introduction to writing in the Humoralphysiologie the Syrian Arab Hunayn ibn Ishaq translator that Isagoge ( Iohanicii ) is called.
  • Boncompagno da Signa (1194-1243), a rhetorician, wrote a Isagoge (also called Ysagoge ) ( Latin text and English translation).
  • Rudolf Goclenius the Elder (1547-1628), Marburg metaphysician who wrote in 1598 a Isagoge in Aristotelis Organum.
  • Julius Sperber (around 1540-1616 ), alchemist and Rosicrucian, wrote in 1608 a Isagoge as "Introduction to the true knowledge of God and of nature."


  • Aristotle, Categories. Hermeneutics or the linguistic expression ( De Interpretatione ), are added to Porphyry: Introduction to the Categories of Aristotle ' ( Isagoge ). Pseudo- Aristotle: Schedule ( Divisiones ). Pseudo- Plato: Definitions ( Definitiones ), edited, translated, provided with introductions and notes by HG Zekl, Greek - German, Hamburg: Felix Meiner Verlag 1998
  • Jonathan Barnes: Porphyry: Introduction. Clarendon Press, Oxford 2003, ISBN 0-19-924614-9 ( English translation of Isagoge with detailed commentary )