How Do Plants Live and Grow? Radical Moisture and Digestion in Albert the Great’s De vegetabilibus

In his De vegetabilibus Albert the Great elaborates a complex physiological explanation in order to describe the vital functions of plants. This explanation is based on some relevant medical doctrines, such as that of radical moisture and digestion, which Albert translates from human into plant physiology. On the basis of these doctrines, Albert develops an intricate system of moistures, by means of which he detailedly explains the generation of each part of plants, such as the leaves, flowers and fruits. In this study, after briefly reconstructing the history of these doctrines, the main aspects of Albert’s plant physiology will be analysed.