The Colour of Dreams
The Colour of Dreams
The Physiology of Oneiric Experience in Greek, Arabic, and Latin Traditions
Marco Signori
23 June 2026 – 5 PM (CEST)
This talk explores the notion of the colour of dreams as it appears in a selection of medieval Arabic and Latin texts on philosophy and medicine. The subject is at the intersection of psychophysiology, medicine, and the doctrine of the rational soul, as it draws on ancient humoral theory in order to explain an intriguing aspect of dream experience that remains a subject of debate.
The idea of a correlation between the colour of oneiric images and the predominance of one of the four humours appears prominently in Avicenna’s (Ibn Sīnā, d. 1037) Canon of Medicine, but also in his philosophical summae, most notably in the Persian Book of Science for ʿAlāʾ al-Dawla, from which it was also picked by the theologian Abū Ḥāmid al-Ġazālī (d. 1111) in his Intentions of the Philosophers.
The source for this connection is a concise yet highly significant doxographic passage attributed to Galen in its sole extant witness, the Arabic MS Baġdād, Awqāf 9763.
Interestingly, however, other Arabic students of this Galenic excerpt on humoral oneirology, such as Abū l-Faraǧ ibn al-Ṭayyib (d. 1043), himself a renowned physician, dropped the references to colour when discussing related issues. Nevertheless, the connection between colour and temperament resurfaces in the Latin tradition, as evidenced by Albert the Great and most notably by Boethius of Dacia, who employed the concept within his scientia somnialis.
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.
About the Speaker ...
Marco Signori is Assistant Professor (RTD-a) in the History of Medieval Philosophy at IMT Lucca.
He studied philosophy at the University of Pisa (BA 2015, MA 2017) and the Scuola Normale Superiore of Pisa (Diploma, 2017), where he also earned his PhD in the History of Medieval Philosophy (2022), under the supervision of Amos Bertolacci. His doctoral dissertation consisted of the first complete English translation, with introduction and an extensive commentary, of Abū Ḥāmid al-Ġazālī’s Intentions of the Philosophers [Maqāṣid al-falāsifa], an encyclopaedic summa of Peripatetic philosophy written in Arabic at the turn of the 12th century. His most recent publications include Al-Ġazālī, The Intentions of the Philosophers, an English translation and commentary of the Maqāṣid al-falāsifa (De Gruyter 2025) and I rami del sapere. Testi arabi sulla classificazione delle scienze (ETS 2025).
