A history of Greek mathematics - Wilbourhall.org

530 COMMENTATORS AND BYZANTINES
number of books which he wrote, including a large number of
commentaries, mostly on the dialogues of PJato (e.g. the
Timaeus, the Republic, the Parmenides, the Cratylus). He
was an acute dialectician and pre-eminent among his contemporaries
in the range of his learning; he was a competent
mathematician ; he was even a poet. At the same time he
was a believer in all sorts of myths and mysteries, and
a devout worshipper of divinities both Greek and Oriental.
He was much more a philosopher than a mathematician. In
his commentary on the Timaeus, when referring to the question
whether the sun occupies a middle place among the
planets, he speaks as no real mathematician could have
spoken, rejecting the view of Hipparchus and Ptolemy because
6 Qzovpyos (sc. the Chaldean, says Zeller) thinks otherwise,
whom it is not lawful to disbelieve '. Martin observes too,
'
rather neatly, that for ' Proclus the Elements of Euclid had
the good fortune not to be contradicted either by the Chaldean
Oracles or by the speculations of Pythagoreans old and new '.
Commentary on Euclid, Book I.
For us the most important work of Proclus is his
commentary
on Euclid, Book I, because it is one of the main sources
of our information as to the history of elementary geometry.
Its great value arises mainly from the fact * that Proclus had
access to a number of historical and critical works which are
now lost except for fragments preserved by Proclus and
others.
(a) Sources of the Commentary.
The historical work the loss of which is most deeply to be
deplored is the History of Geometry by Eudemus. There
appears to be no reason to doubt that the work of Eudemus
was accessible to Proclus at first hand. For the later writers
Simplicius and Eutocius refer to it in terms such as leave no
doubt that they had it before them. Simplicius, quoting
Eudemus as the best authority on Hippocrates's quadratures
of lunes, says he will set out what Eudemus says * word for
word ', adding only a little explanation in the shape of references
to Euclid's Elements 'owing to the memorandum-like
style of Eudemus, who sets
out his explanations in the abbre-