Eutocius
Εὐτόκιος
(Εὐτόκιος) of Ascalon, the commentator on Apollonius of Pesga and on Archimedes, must have lived about A. D. 560.
At the end of some of his commentaries on Archimedes he says he used " the edition recognised by Isidore of Miletus, the mechanic, our master." This Isidore was one of Justinian's architects, who built the church of St. Sophia.
Works
Mathematical Works
The Greek originals of the following works of Eutocius are preserved: Commentaries on the first four books of the Conics of Apollonius On the Sphere and Cylinder On the Quadrature of the Circle On the Two Books on Equilibrium, of Archimedes.
These commentaries were of ordinary value, as long as geometrical help in understanding the text was required. Torelli wishes that Eutocius had applied himself to all the writings of Archimedes. But they have a merit which will preserve them, independently of their mathematical value; they contain incidentally so much information on the lost writings of Greek geometers, and on the methods of Greek arithmetic, that they are integrant parts of the history of Greek learning. Torelli found them frequently give, by way of citation, a more satisfactory text of Archimedes than that of the remaining mannscripts, which he attributes to the goodness of Isidore's edition: haec causa fuit, cur Archimedem in Eutocii domo conquirerem ubi melius quandoque quam in propria habitabat.
Editions
These have been printed in the Greek edition of APOLLONIUS, and in the two Greek editions of ARCHIMEDES.
Latin versions have been given with several of the versions of these two writers, sometimes complete, sometimes in part.
There has been no separate print of Eutocius.
Further Information
Torelli Pref. in Archimed.; Fabric. Bibl. Graec. vol. iv. p. 203.
From William Smith (ed.), Dictionary of Greek and Roman Biography and Mythology. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.