La physiologie de l'expérience onirique dans les traditions grecque, arabe et latine

The Colour of Dreams. The Physiology of Oneiric Experience in Greek, Arabic, and Latin Traditions



CSMBR Upcoming Lecture


Marco Signori


23 June 2026 – 5 PM (CET)


This talk explores the concept of dream colour as it appears in a selection of medieval Arabic and Latin philosophical and medical texts. Lying at the intersection of psychophysiology, medicine and the doctrine of the rational soul, this subject draws on ancient humoral theory to explain an intriguing aspect of the dream experience. 

The idea of a correlation between the colour of oneiric images and the predominance of one of the four humours originates from a concise yet highly significant doxographic passage attributed to Galen, as recorded in the only surviving manuscript, Arabic MS Baġdād (Awqāf 9763), and is referenced in notable resources such as Avicenna's (Ibn Sīnā, d. 1037) writings and the Persian Book of Science for ʿAlāʾ al-Dawla.

Curiously, however, while other Arabic students of this Galenic excerpt on humoral oneirology, such as Abū l-Faraǧ ibn al-Ṭayyib (d. 1043), omitted references to colour when addressing related topics, this connection reemerges in the Latin tradition, as demonstrated by Albert the Great and, most notably, Boethius of Dacia.

Building on previous scholarship and analysing various intermediary channels, the contribution will discuss the possible historical and doctrinal links between these authors, tracing hypothetical lines of transmission from Greek-Arabic medicine to 13th-century Latin philosophy.


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