Su quale fianco è meglio dormire? Le soluzioni a un'antica questione, dai Problemata pseudo-atistotelici a Pietro d'Abano.

This contribution offers the first comprehensive reconstruction of the solutions provided by the ancient and medieval medical and philosophical tradition (from the late 4th century B.C. to the 14th century) to the question of the best position for sleeping. Particular attention is paid to the pseudo-Aristotelian Problemata and Secretum secretorum, to three passages from Avicenna’s Canon (in partial contradiction to each other), to the regimina sanitatis tradition, and to the articulate reception of these works by Peter of Abano. In his Conciliator, differentia 123, and even more so in the Expositio problematum, Peter demonstrates original syncretism and depth in explaining the alternating position of sidesleeping (which affects digestion), adding some reflections on the role of spirits and light that no other author, beyond Pseudo-Aristotle, had mentioned.