Aristotle’s well-known definition of the soul is found in On the Soul 2.1, 412a19: the soul is the form or actualization (entelekheia) of a natural or organic body which potentially has life. In other words, the soul is the principle through which living beings are alive and have different capacities such as nutrition, reproduction, perception, desire, and thinking. Non-human animals and plants share the most basic capacities, i.e. nutrition and reproduction. Perception and desire, however, are powers that pertain to non-human and human animals. Within his biological treatises Aristotle conceived a sort of phylogenetic scale, according to which inferior non-human animals possess at least the sense of touch while higher forms of life, for instance mammals, have five external senses and more complex capacities such as common sense, memory, and imagination. Human animals share the capacities performed by plants and non-human animals, but in the particular case of humans an exclusive and unique capacity is added: thinking. When dealing with those capacities shared by human and non-human animals, i.e.

perception, it is not clear whether Aristotle is explaining this capacity and others related to it (appetite, desire, pleasure and pain, etc.) through the soul, or if, on the contrary, the soul is explained by means of perceptive operations. Aristotle’s standard position is that these capacities are common to both body and soul. However, as some scholars have shown (Morel 2006: 121; Sharples 2006: 165; Rapp 2006: 187), this alternative is problematic since it is not clear in which sense “common” should be understood. My intention here is not to go into this discussion in the Aristotelian corpus. This problem, however, serves to contextualize some issues that were at the heart of Arabic-Islamic medieval philosophical psychology: the relationship between body and soul, the cognitive capacities of the soul, the immortality of the human soul, and the knowledge of the self. The understanding of these issues had a strong Aristotelian background. Arabic-

Islamic philosophers were influenced by Aristotelian treatises such as On the Soul (Kita-b al-Nafs), related treatises known collectively as the Parva Naturalia, and also by Aristotle’s writings on animals (History of Animals, Parts of Animals, Movement of

Animals, Progression of Animals, and Generation of Animals), all of which were gathered under the name of Book of Animals (Kita-b al-haya-wa-n). In these main treatises devoted to the investigation of living beings it becomes quite evident that Aristotle considers the study of the soul as part of the natural sciences. Although this kind of approach was very influential to Arabic-Islamic philosophers, it was somewhat problematic: Aristotle held the unity of body and soul but he also described the body as an instrument of the soul, as though the two were different substances. Furthermore, given his definition of the soul as the substantial form of the body, he claimed that this relationship ceases when the body perishes and seems to have left little or no room for human individual immortality. Islamic philosophers were concerned about these issues and discussed different matters in depth-such as the origination of the soul and its relationship to the body, the distinction between the cognitive operations that rely on the body and those intellective operations that do not depend on it-and they tried to define the ontological status of the soul in efforts to determine whether it is immortal. The relationship between body and soul in Aristotle’s philosophical psychology

is difficult to grasp. Modern and contemporary discussions on philosophy of mind have put aside Aristotle and those traditions that built their views on these matters upon Aristotelian foundations, and hence have treated the question of the relationship between body and soul as if it were exclusively a modern problem. In fact, it is a commonplace to attribute the beginning of philosophy of mind to Descartes and his distinction between res cogitans and res extensa. There are, however, reasons to hold that it actually started with Ibn Sı-na-and his understanding of Aristotle’s On the Soul (Lagerlund 2007a: 1-16, 2007b: 11-32; Kaukua & Kukkonen 2007: 95-119). In what follows, I shall explain the way in which Ibn Sı-na-(d. 1037) and Ibn Rushd (d. 1198) understood the relationship between body and soul and some related issues such as perception, self-awareness, intellection, and the immortality of the soul. There were different approaches to the Aristotelian philosophical psychology in the

Arabic-Islamic context. For example, there are several treatises where al-Kindı-(d. 870) deals with psychological matters displaying a strong Aristotelian and Neoplatonic background, but it is difficult to integrate his ideas into a coherent theory (Adamson 2007: 106-43). Al-Fa-ra-bı-(d. 950) also wrote the Epistle on the Intellect (Risa-lat fi al ‘aql), which envince quite clearly the influence of Aristotle’s doctrine of the soul and its interpretation by Alexander of Aphrodisias. Although both philosophers made early valuable contributions to the understanding of the soul and its relationship with the body, Ibn Sı-na-’s and Ibn Rushd’s approaches to this matter were more highly systematic. In his psychological writings Ibn Sı-na-did not intend to expound and clarify

Aristotle’s standpoint. Rather, as a result of his reading of the pseudo-Aristotelian work Theology of Aristotle, and some Neoplatonic writings on the soul, he somewhat distanced himself from Aristotle’s doctrine of the soul. This led him to a different and original perspective wherein the soul is conceived as an independent, individuated, and immortal substance. In contrast, in his three commentaries on Aristotle’s On the Soul, Ibn Rushd went through Aristotle’s text in detail, trying to establish its correct understanding and mend some of the misunderstandings of his predecessors

(al-Fa-ra-bı-, Ibn Sı-na-, Ibn Ba-jja). Ibn Rushd’s commentaries are different from each other but they also have something in common: as Aristotle before him, in all three commentaries, Ibn Rushd considered the study of the soul as related to the natural sciences. What both Ibn Sı-na-and Ibn Rushd have in common is their conception of intellectual understanding as something that goes beyond the bodily powers.