"We shall often... have occasion to quote from the so-called 'Summary' of Proclus... Occupying a few pages of Proclus's Commentary on Euclid, Book I, it reviews, in the briefest possible outline, the course of Greek geometry from the earliest times to Euclid, with special reference to the evolution of the Elements. At one time it was often called the 'Eudemian summary', on the assumption that it was an extract from the great History of Geometry in four Books by Eudemus, the pupil of Aristotle. But a perusal of the summary itself is sufficient to show that it cannot have been written by Eudemus; the most that can be said is that, down to a certain sentence, it was probably based, more or less directly, upon data appearing in Eudemus's History."