Treasures of the Bodleian

This is the oldest surviving manuscript of what would become the standard version of Euclid’s Elements, as re-edited in the fourth century AD by Theon of Alexandria. Theon standardized Euclid’s style and vocabulary, and expanded numerous passages with a view to helping the reader. The manuscript is open to show Euclid’s definition of the golden ratio, or divine proportion: ‘A straight line is said to have been to have been cut in extreme and mean ratio when, as the whole line is to the greater segment, so is the greater to the less.’ For millennia, the unique properties of this ratio have been explored by mathematicians, biologists, artists, architects, musicians and, more recently, economists.

Excerpt of the Elements of Euclid (in Greek), read by Cressida Ryan

Excerpt of the Elements of Euclid (in English), read by Cressida Ryan