SOURCE: "The History of Geometry to the Time of Euclid: Commentary on Euclid's 'Elements I,'" in A Source Book In Greek Science, edited by Morris R. Cohen and I. E. Drabkin, translated by I. E. Drabkin, McGraw-Hill Book Company, Inc., 1948, pp. 33-85.

In the following excerpt—with translation by Drabkin and notes by Cohen and Drabkin, Proclus offers a brief overview of geometry, from that of the ancient Egyptians up to that of Euclid's Elements.

We must next speak of the origin of geometry in the present world cycle. For, as the remarkable Aristotle tells us, the same ideas have repeatedly come to men at various periods of the universe. It is not, he goes on to say, in our time or in the time of those known to us that the sciences have first arisen, but they have appeared and again disappeared, and will continue to...