), one of the latest commentators on Aristotle, lived about the beginning of the twelfth century after Christ, under the emperor Alexius Comnenus, as metropolitan of Nicaea.
According to a hint in the Commentary to the tenth book of the Ethica Nicomachea
(if this part of the Commentary is composed by him), he appears to have also lived at Constantinople, and to have written his commentary in this place. (Comp. ad Arist. Eth. Nic.
10.9.13, p. 472, ed. Zell.) Of his life we know nothing else.
Of the writings of Eustratius only two are extant, and these in a very fragmentary state: viz.
A Commentary to the second hook of the Analytica
Published by Aldus Manutius, Venice, 1534
, and translated into Latin by A. Gratarolus. (Venice. 1542, 1568, fol.)
A Commentary to Aristotle's Ethica Nicomachea
But, according to the latest researches, this commentary consists of very different materials, and great parts of it are the work of other interpreters, as Aspasius and Michael Ephesius.
This has been proved chiefly by the researches of Schleiermacher, in his writings on the Greek Scholia to the Ethics of Aristotle (printed in the Abhandlungen der Berliner Akademie der Wissensch.
of the year 1816-1817, p. 263, &c.). Schleiermacher has shewn that the author of the commentary to the first
book of the Ethics cannot possibly be the same person as the author of the comnmentary to the sixth
book, because very different interpretations of the Ἑχωτερικοὶ Αόγοι
of Aristotle are given in the two passages cited. (See Stahr, Aristotelia,
ii. pp. 261, 262; Schleiermacher, p. 267.) Probably Eustratius is only the author of the commentary to the sixth book, which is much better than the rest, and from which the commentaries to the second, third, and fourth book greatly differ.
But perhaps the commentary to the first
is also to be ascribed to Eustratius, and the difference on the signification of the Ἑχωτερικοὶ Αόγοι
may have been occasioned by Eustratius himself borrowing one opinion or the other from more ancient interpreters.
Published in the Greek language with some other commentators on the same work, Venice, 1536, fol.
, and in the Latin language by J. Bernardus Felicianus, Ven. 1541, 1589, fol, Paris. 1543, Helmst. 1662, 4to.
The commentaries of Eustratius greatly differ from similar works of elder commentators by their not being uninterrupted treatises on philosophical subjects, but commentaries
in the proper sense of the word, explaining single words and things.
It is this which renders them of great importance.
In the middle ages Robert of Lincoln translated this commentary into Latin, and Albertus Magnus and St. Thomas Aquinas made considerable use of it in their interpretation of Aristotle.
Fabric. Bibl. Graec.
vol. iii. pp. 215, 264; Buhle's Aristotle,
vol. i. p. 299.