Peterhouse : The De Aspectibus of Alhacen

Peterhouse

A copy of De Aspectibus (or Optica), a Latin translation of an Arabic manuscript made around 1200. The work - which had only just reached the Latin West - was the Kitab al-Manazir (Book of Optics) written by the Islamic polymath Abū ʿAlī al-Ḥasan ibn al-Ḥasan ibn al-Haytham in Cairo.It has the incipit Invenimus visum quando inspexerit luces valde fortes . . . “We find that when sight fixes on very strong light . . .” Above the incipit is written de luce in the same hand as that of the text. The De Aspectibus is on folios 1-111 and De Crepusculis is on folios 112-118. The second work is attributed to Alhacen in the manuscript, but it is the work of Ibn Muʿādh. ibn al-Haytham was born around 965 in Basra in what is now Iraq. In 1020 he moved to Cairo where he worked until his death in about 1040. The Kitab al-Manazir, thought to have been written between 1028 and 1038, is one of many works in natural philosophy attributed to ibn al-Haytham. A copy of the holograph, made by his son-in-law, resides in the Süleymaniye Library in Istanbul.A century earlier, the Arabic text appeared in the West and was translated into Latin no later than 1210. Importantly, the first three chapters of Book 1 are not in the translation and so the material dealing with the fundamental physical aspects of light never reached the West. Though Gerard of Cremona is usually thought to be the translator, there is no definite evidence for this, and some against. It is certain that the translation is the work of two individuals: one produced a Latin that kept very close to the Arabic, the other produced a summary or paraphrase. The translator(s) chose the title De Aspectibus, and it was with that title that copies of the translation began to be made and circulate. al-Ḥasan ibn al-Haytham was Latinized to “Alhacen” and so the medieval manuscript tradition had Alhacen as the author.This Peterhouse copy dates to the early 1300s and was bequeathed to the College in 1371. It is one of 20 manuscripts of the De Aspectibus listed by Lindberg and is further described by James. - David DiLaura