ABSTRACT
This chapter explores the importance of light in the early promotion of the cult of St. Thomas Aquinas in the first half of the 14th century. Representations of divine illumination are found in pictures of Annunciation where rays are used to symbolise the transmission of the Word to the Virgin, in pictures of the Stigmatisation of St. Francis, and in some images of Christ where he is shown with a surrounding luminescence. The first and largest of the Mendicant Orders of friars were the Franciscans, founded in 1209, and the Dominicans, founded in 1216. Both Orders expanded rapidly in the 13th century and attracted some of the finest teachers and scholars of the time – and it was these friars who took the lead in the 13th century in thinking about light and optics. The book held by Aquinas bears the same inscription as appears on his book in the Simone Martini Polyptych, the incipit from the Summa contra Gentiles.
