A part of chapter 1, Book II of the Physics of the šif¯' is dedicated to the aristotelian definition of motion (Physics III, 1, 201a10-11). The developments to which the treatment of this question gives rise are distinctive of the Avicennian style in his Physics. By assuming the notion of double entelechy, Avicenna is following the most classical exegetical tradition. However, by setting a correspondence between the double entelechy and the double notion of motion: 1) motion as an intermediary state, which can be ascribed to a moving object at any instant of its trajectory, and 2) motion as a traversal of a given distance, which cannot be ascribed to the moving object, but at the end-point of its trajectory, Avicenna gives a new content to a lieu commun of the exegetical tradition.