In metaphysics, Avicenna refers to the heaven as animal (ḥayawān), and to its proximate principle of motion as soul (nafs), by using the same terminology used in psychology to refer to sublunary animals and their principle. The strategy behind this approach is to account for a remote phenomenon, i.e. heavenly circular motion, through the account of an analogous but closer and thus more knowable phenonemon, i.e. animal locomotion. Thus, in metaphysics, a sort of continuity between sublunary and celestial ‘animals’ seems to be posited: both are defined by means of the same terminology and share in some distinctive features. However, in psychology, where this terminology is defined, Avicenna explicitly denies that sublunary and celestial ‘animals’ can be referred to in the very same way, except by equivocation. This position rests on the discontinuity between the sublunary and celestial realms that is posited in psychology. Given that Avicenna’s attitude towards this issue is not consistent, the aim of this chapter is to shed some light on the use of the terms animal and soul in psychology and in metaphysics, in order to ascertain whether they have the same meaning when they are applied to celestial and sublunary entities.