Late ancient and early medieval narratives often depict dreaming as a vertical and hierarchical process of influence that has its starting point in a higher entity and ends with the human being. This model of explanation seems to take a more horizontal approach with the advent of a new natural philosophy and medical works from Arabic milieu that put the psychosomatic processes of the human being into perspective. The general purpose of this paper is to assess to which extent Albert (...) the Great’s consideration of dreams can be taken as an example of this turning point. Specifically, it tries to show how his dream theory is articulated in De homine. The main hypothesis is that the Dominican friar advocated a materialistic account of dreams, in which the process of dream formation is explain as a flux of bodiness caused by a change in the thermal behavior of the body. (shrink)