''On Ideas'' (

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

: Περὶ Ἰδεῶν, ''Peri Ideōn'') is a philosophical work which deals with the

problem of universals The problem of universals is an ancient question from metaphysics that has inspired a range of philosophical topics and disputes: Should the properties an object has in common with other objects, such as color and shape, be considered to exist be ...

with regards to Plato's

Theory of Forms The theory of Forms or theory of Ideas is a philosophical theory, fuzzy concept, or world-view, attributed to Plato, that the physical world is not as real or true as timeless, absolute, unchangeable ideas. According to this theory, ideas in th ...

. The work is supposedly by

Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of phil ...

, but there isn't universal agreement on this point. It only survives now as fragments in quotations by

Alexander of Aphrodisias Alexander of Aphrodisias ( grc-gre, Ἀλέξανδρος ὁ Ἀφροδισιεύς, translit=Alexandros ho Aphrodisieus; AD) was a Peripatetic school, Peripatetic philosopher and the most celebrated of the Ancient Greek Commentaries on Aristo ...

in his commentary of Aristotle's ''

Metaphysics Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...

''.

Summary

''On Ideas'' gives greater detail to many of the arguments which Aristotle recounts in ''Metaphysics'' A.9. There and here objections to arguments for Plato's theory of Forms are given. A point made in multiple places is that the Platonist arguments establish only that there are universals in a general and metaphysically slim sense, and not there are full-blown Forms of the Platonic kind. A version of the third man argument is also given.

Authenticity

Alexander of Aphrodisias does attribute his quotations which form the extant text of ''On Ideas'' to Aristotle. The content also matches with what Aristotle says of the Platonist arguments in his ''Metaphysics''. However, the external evidence that ''On Ideas'' is an authentic work of Aristotle is ambiguous and its status as such is not universally recognized.Michael L. Morgan, Review of Fine's 1993 ''On Ideas'' i
The Metaphysics Review, Vol. 45, no. 1 (1995), pp. 132-134

Text and translations

The full Greek text of Alexander's commentary which includes ''On Ideas'' is published in the first volume of the ''

Commentaria in Aristotelem Graeca ''Commentaria in Aristotelem Graeca'' 'edita consilio et auctoritate academiae litterarum Regiae Borussicae''(''CAG'') (Greek Commentaries on Aristotle dited by order and auctority of the Prussian Royal Academy of literary studies is the standa ...

''. Excerpts from this, along with an English translation and commentary by

Gail Fine Gail Fine is a professor of philosophy emerita at Cornell University. She was also a visiting professor of ancient philosophy at Oxford University, and a senior research fellow at Merton College, Oxford University. Education and career Fine earn ...

, are available in ''On Ideas: Aristotle's Criticism of Plato's Theory of Forms'' published by the Oxford University Press in 1993. This translation is also reproduced with notes in ''Aristotle: Selections'', edited by Terence Irwin and Gail Fine and published by Hackett Publishing in 1995.

References

Classical Greek philosophical literature Metaphysics literature {{metaphysics-book-stub